Patent Publication Number: US-2022219040-A1

Title: Tilt-enabled bike with tilt-disabling mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application of U.S. application Ser. No. 17/122,861, filed Dec. 15, 2020, which claims priority to U.S. Provisional Application Ser. No. 62/953,688, filed Dec. 26, 2019 and U.S. Provisional Application Ser. No. 63/038,482, filed Jun. 12, 2020, which provisional applications are incorporated herein by reference in their entirety for any purposes. 
    
    
     FIELD 
     The present disclosure relates generally to a stationary exercise machine and more specifically to a stationary bike which is selectively reconfigurable between a tilt-enabled stationary bike to a non-tiltable (or fixed) stationary bike. 
     BACKGROUND 
     A stationary exercise machine designed to simulate cycling is often referred to as stationary bike or spin bike. Such stationary bikes typically have a driven assembly including a crank wheel, a pair of cranks fixed to the crank wheel to drive rotation of the crank wheel and each terminating in respective pedal. The crank wheel is typically connected, via any suitable transmission member such as a belt or a chain, to a resistance mechanism, for example a magnetically or frictionally resisted flywheel. As such a stationary bike is able to simulate much of the physical exertion applied when a riding a bike, and thus provides a reasonably good cardiovascular exercise. However, because a stationary bike is more stable when used (due in part to being fixed to one or more non-moving frame(s)) than a real bicycle, a stationary bike may not be able to allow the user to engage certain muscle groups (e.g., the user&#39;s abdominal core and/or upper body) at all or to a same or similar extent as when riding a real bicycle. Therefore designers and manufacturers of exercise equipment continue to seek improvements in the field of stationary bikes. 
     SUMMARY 
     In various embodiments, a stationary bike is disclosed, which is selectively reconfigurable between a tilt-enabled stationary bike to a non-tiltable (or fixed) stationary bike. 
     Embodiments of a tilt-enabled exercise bike with a tilt-disabling mechanism are described. In some embodiments, the exercise bike includes a first frame that remains substantially stationary with respect to a support surface, a second frame pivotally joined to the first frame and configured to support a user, the second frame pivoting relative to the first frame about a pivot axis in response to a force applied to the second frame by the user. The exercise bike further includes a locking mechanism operatively associated with the first and second frames and actuatable to an engaged state that prevents pivotal movement of the second frame relative to the first frame. In some embodiments, the locking mechanism comprises a pin coupled to one of the first and second frames and a corresponding hole that receives the pin, the hole being coupled to the other one of the first and second frames. In some embodiments, the pin may be coupled to the first or second frames such that it extends in a direction that intersects with the pivot axis and is selectively movable toward and away from the pivot axis. In some embodiments, the second frame is pivotally supported on the fixed frame by at least one pivot shaft that defines the pivot axis. In some embodiments, the pivot axis extends in substantially the same direction as the longitudinal axis of the exercise bike. In some embodiments, the second frame is pivotally supported on the fixed frame via a front pivot shaft and a rear pivot shaft axially aligned to define the pivot axis. In some embodiments, the locking mechanism selectively engages at least one of the one or more pivot shafts that pivotally couple the moving frame to the fixed frame (e.g. the front pivot shaft and/or the rear pivot shaft) to resist the rotation of the front pivot shaft or the rear pivot shaft. In some embodiments, the locking mechanism includes a friction brake operatively associated with the front pivot shaft or the rear pivot shaft. In some embodiments, the locking mechanism includes a magnetic brake operatively associated with the front pivot shaft or the rear pivot shaft. In some embodiments, the locking mechanism includes a block coupled to one of the first frame and the second frame and a wedge coupled to the other one of the first frame and the second frame, at least one of the block and the wedge being movably coupled to the respective frame to cause the at least a portion of the wedge to be received in a groove of the block when the block and the wedge are brought closer together for at least one position of the second frame relative to the first frame. In some embodiments, the block pivotally is coupled to the second frame and the wedge fixed to the first frame. In some embodiments, the block is pivotally coupled to one of the first frame and the second frame and the wedge is fixed to the other one of the first frame and the second frame, the locking mechanism being operatively associated with an actuator configured to pivot or slide the block toward and away from the wedge. In some embodiments, the actuator includes a spring connecting the actuator to the block for transmitting actuation force to the block. In some embodiments, the actuator is positioned on the bike such that it is accessible to the user while riding the bike. In some embodiments, the exercise bike further comprises a drive assembly including a crankshaft operatively associated with a pair of pedals configured to be driven by the user, the second frame being pivotally coupled to the first frame at a first pivot joint located forward of the crankshaft and a second pivot joint located aft of the crankshaft. In some embodiments, the first frame includes a base having a front and rear stabilizers. In some embodiments, the pivot axis of the bike is inclined at an angle no greater than 45 degrees relative to a base plane passing through the front and rear stabilizers. In some embodiments, the exercise bike further include a damper that resists the pivotal movement of the second frame relative to the first frame. In some embodiments, the damper includes at least one spring operatively positioned to resist the pivotal movement of the second frame relative to the first frame. In some embodiments, the damper includes a first spring positioned vertically above the pivot axis and a second spring positioned vertically below the pivot axis. In some embodiments, each of the first and second springs are fixed to the second frame. In some embodiments, the bike further includes a display that remains stationary with respect to the first frame while the second frame pivots relative to the first frame. In some embodiments, the display is mounted on a mast fixed to and extends from the first frame. In some embodiments, the display is pivotally mounted to the mast, whereby pivoting of the display adjusts a viewing angle of the display. In some embodiments, the locking mechanism is operatively associated with an actuator configured for remote actuation. 
     An exercise bike according to some embodiments of the present disclosure includes a first frame that remains substantially stationary with respect to a support surface, a second frame pivotally joined to the first frame and configured to support a user, the second frame pivoting relative to the first frame about a pivot axis in response to a force applied to the second frame by the user, and a display mounted on a structural member fixed to and extending from the first frame. In some embodiments, the display is pivotally mounted on the structural member. In some embodiments, the exercise bike further includes an arm having a first end pivotally coupled to the mast and wherein the display is coupled to a second end of the arm opposite the first end. In some embodiments, the arm is curved along at least a portion of the arm between the first end and the second end, and the arm may be slidably or pivotally coupled to the structural member. In some embodiments, the structural member may be a mast. In some embodiments, the exercise bike may further include a locking mechanism operatively associated with the first and second frames and actuatable to an engaged state that prevents pivotal movement of the second frame relative to the first frame. In some embodiments, the locking mechanism includes a pin coupled to one of the first and second frames and a corresponding hole that receives the pin, the hole being provided by a structure coupled to the other one of the first and second frames. In some embodiments, the second frame is pivotally supported on the fixed frame by at least one pivot shaft that defines the pivot axis. In some embodiments, the locking mechanism is operatively associated with the at least one pivot shaft to substantially prevent rotation about the pivot axis in at least one state of the locking mechanism. In some embodiments, the locking mechanism includes a block coupled to one of the first and second frames and a wedge coupled to the other one of the first and second frames, at least one of the block and the wedge being movable toward the other one of the block and the wedge to provide the locking mechanism in an engaged position in which the block interferes with the wedge. 
     An exercise bike system according to some embodiments includes a first bike frame that remains substantially stationary with respect to a support surface, a second bike frame pivotally joined to the first frame and configured to support a user, the second frame pivoting relative to the first frame about a pivot axis in response to a force applied to the second frame by the user, and at least one sensor attached to either the first or second bike frame. The exercise bike system further includes a transceiver attached to either the first or second bike frame and in communication with the sensor, a stand unattached to either of the first and second bike frames, and a display supported by the stand and in communication with the transceiver, the display remaining stationary with respect to the first bike frame while the second bike frame pivots relative to the first bike frame. In some embodiments, the at least one sensor includes a cadence sensor, a power sensor, a position sensor, or a tilt sensor. In some embodiment, the sensor is operatively associated with pivot axis to measure an amount of rotation of the second bike frame relative to the first bike frame. In some embodiment, the exercise bike system further includes a locking mechanism operatively associated with the first and second bike frames and actuatable to an engaged state that prevents pivotal movement of the second bike frame relative to the first bike frame. 
     An exercise bike according to some embodiments includes a first frame that remains substantially stationary with respect to a support surface, a second frame pivotally joined to the first frame and configured to support a user, wherein the second frame pivots relative to the first frame about a pivot axis in response to a force applied to the second frame by the user, and a display mounted on a structural member fixed to and extending from the first frame. In some embodiments, the display is pivotally mounted on the structural member. In some embodiments, the structural member comprises a mast. In some embodiments, the exercise bike further comprises an arm having a first end pivotally coupled to the structural member and wherein the display is coupled to a second end of the arm opposite the first end. In some embodiments, the arm is curved along at least a portion of the arm between the first end and the second end, and wherein the arm is slidably or pivotally coupled to the structural member. In some embodiments, the exercise bike further comprises a locking mechanism operatively associated with the first and second frames and actuatable to an engaged state that prevents pivotal movement of the second frame relative to the first frame. In some embodiments, the locking mechanism comprises a pin coupled to one of the first and second frames and a corresponding hole that receives the pin, wherein the hole is coupled to the other one of the first and second frames. In some embodiments, the second frame is pivotally supported on the first frame by at least one pivot shaft that defines the pivot axis. In some embodiments, the locking mechanism is operatively associated with the at least one pivot shaft to substantially prevent rotation about the pivot axis in at least one state of the locking mechanism. In some embodiments, the locking mechanism comprises a block coupled to one of the first and second frames and a wedge coupled to the other one of the first and second frames, wherein at least one of the block and the wedge is movable toward the other one of the block and the wedge to provide the locking mechanism in an engaged position in which the block interferes with the wedge 
     A tilt-enabled exercise bike according to further embodiments includes a drive assembly including a crankshaft and a pair of pedals, each coupled to an opposite side of the crankshaft, for rotation of the crankshaft by a user, and a frame rotatably supporting the crankshaft. The frame includes a base that supports the exercise bike on a support surface, the base having first and second lateral ends disposed on opposite sides of the frame that move relative to the supports surface when the user is rotating the crankshaft, and the tilt-enabled exercise bike further includes a tilt-disabling mechanism operatively associated with the base to disable the movement of the first and second lateral ends relative to the support surface. In some embodiments, the base includes at least one curved member having a convex side that contacts the support surface whereby the opposite lateral ends of the curved member are spaced from the support surface, and the tilt-disabling mechanism includes at least one adjustable member movably coupled to each of the opposite lateral ends and adjustable to contact the support surface. In some embodiments, the at least one adjustable member comprises a spring element fixedly coupled to a midpoint of the curved member and extending lengthwise along the curved member to at least one of the lateral ends of the curved member, the spring element being movable relative to the lateral end for adjusting a distance between the spring element and the lateral end. In some embodiments, the at least one adjustable member includes an adjustable foot coupled to one of the lateral ends of the curved member. In some embodiments, the adjustable foot is movable along a length of the curved member. In some embodiment, the tilt-disabling mechanism includes at least one compressible foot coupled to each of the first and second lateral ends. In some embodiments, the one or more compressible feet may be implemented using a reversibly compressible (e.g., compliant or resilient) element such as a spring. 
     This summary is neither intended nor should it be construed as being representative of the full extent and scope of the present disclosure. The present disclosure is set forth in various levels of detail in this application and no limitation as to the scope of the claimed subject matter is intended by either the inclusion or non-inclusion of elements, components, or the like in this summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate examples of the disclosure and, together with the general description given above and the detailed description given below, serve to explain the principles of these examples. 
         FIG. 1  is an isometric view of a stationary bike according to the present disclosure. 
         FIG. 2  is a side view of the bike of  FIG. 1  shown here with a console mounted to the fixed frame. 
         FIG. 3  is another isometric view of the bike in  FIG. 1  shown here with the bike in a tilted position. 
         FIGS. 4A and 4B  show rear downward views of the bike in  FIG. 1 , showing the bike in an un-tilted (nominal) position and a tilted position, respectively. 
         FIG. 5  is a partial cross-sectional view taken at line  5 - 5  in  FIG. 1 , illustrating the front and rear pivot joints and the tilt axis of the moving frame. 
         FIG. 6A  shows an exploded view of the rear pivot joint of the bike in  FIG. 1 , as indicated by detail line  6 A- 6 A in  FIG. 5 . 
         FIG. 6B  shows an exploded view of the front pivot joint of the bike in  FIG. 1 , as indicated by detail line  6 B- 6 B in  FIG. 5 . 
         FIGS. 7A and 7B  show cross-sectional views, in a disengaged position and an engaged position, respectively, of a tilt-lock assembly for use with the bike in  FIG. 1  according to some examples of the present disclosure. 
         FIGS. 7C and 7D  show cross-sectional views, in a disengaged position and an engaged position, respectively, of a tilt-lock assembly for use with the bike in  FIG. 1  according to further examples of the present disclosure. 
         FIG. 8A  shows an exploded view of the tilt-lock assembly shown in  FIGS. 7A and 7B . 
         FIG. 8B  shows an exploded view of the tilt-lock assembly shown in  FIGS. 7C and 7D . 
         FIG. 9A  is an isometric view of a portion of the tilt-lock assembly in  FIG. 7A , shown in a disengaged position. 
         FIG. 9B  is another isometric view of the portion of the tilt-lock assembly shown in  9 B, with the lock block actuated to the locked position while the bike is in a tilted (or off-center) position. 
         FIG. 9C  is yet another isometric view of the portion of the tilt-lock assembly shown in  9 A, with the locking mechanism engaged. 
         FIG. 10A  shows a bottom view of the portion of the tilt-lock assembly in  FIG. 9A . 
         FIG. 10B  shows a bottom view of the portion of the tilt-lock assembly in  FIG. 9B . 
         FIG. 10C  shows a bottom view of the portion of the tilt-lock assembly in  FIG. 9C . 
         FIGS. 11A and 11B  are views of another example of a tilt-lock assembly for the bike in  FIG. 1 , shown in an engaged position and a disengaged position, respectively. 
         FIG. 12  show a side view of the tilt-enabled bike of  FIG. 1  with a tilt-disabling mechanism according to the present disclosure. 
         FIG. 13  shows a simplified cross-sectional view of the tilt-disabling mechanism in  FIG. 12   
         FIG. 14  shows another example of a tilt-disabling mechanism for the bike in  FIG. 12   
         FIG. 15  shows yet another example of a tilt-disabling mechanism for the bike in  FIG. 12 . 
         FIGS. 16A and 16B  are schematic illustrations of further tilt-disabling mechanisms in accordance with the present disclosure. 
         FIGS. 17A and 17B  show a simplified illustration of a tilt-disabling mechanism in an engaged and disengaged state, respectively, in accordance with further examples of the present disclosure. 
         FIG. 18  is a schematic illustration of a pin-in-hole tilt-disabling mechanism in accordance with the present disclosure. 
         FIGS. 19A and 19B  show further examples of pin-in-hole tilt-disabling mechanisms for a tilt-enabled bike according to the present disclosure. 
         FIG. 20A  is a front view of yet another example of a tilt-disabling mechanism, shown in the engaged position, for a tilt-enabled bike according to the present disclosure. 
         FIG. 20B  is an isometric view of the tilt-disabling mechanism of  FIG. 20A , shown in the disengaged position. 
         FIG. 20C  is a side view of the tilt-disabling mechanism of  FIG. 20B  in the disengaged position. 
         FIG. 20D  is a side view of the tilt-disabling mechanism of  FIG. 20A , shown in the engaged position. 
         FIG. 21A  shows yet another tilt-disabling mechanism on a tilt-enabled bike in accordance with the present disclosure. 
         FIG. 21B  shows a simplified illustration of the tilt-disabling mechanism of  FIG. 21A . 
         FIGS. 22A and 22B  show simplified illustrations of further examples of a tilt-disabling mechanism. 
         FIG. 23  shows a damper for resisting the tilting movement of the bike in  FIG. 1 . 
         FIG. 24  shows a simplified cross-sectional view of a tilt-disabling mechanism according to further examples herein. 
         FIG. 25  is a view of the tilt-disabling mechanism of  FIG. 24  viewed along the axial direction. 
         FIGS. 26A and 26B  show a tilt-disabling mechanism according to further examples herein. 
         FIGS. 27A-27C  show a tilt-disabling mechanism according to yet further examples of the present disclosure. 
         FIG. 28  shows a tilt-enabled bike with a rocking base according to embodiments of the present disclosure. 
         FIGS. 29A and 29B  show views of a rocking base for a tilt-enabled bike according to further examples herein. 
         FIGS. 30A and 30B  show view of a support base for a tilt-enabled bike with according to embodiments of the present disclosure. 
         FIGS. 31A and 31B  show further examples of exercise bike systems in accordance with the present disclosure. 
         FIG. 32  shows an exercise system including a tilt-enabled bike configured for remote actuation of the tilt-disabling mechanism in accordance with the present disclosure. 
         FIGS. 33A and 33B  show illustrations of a coded wheel tilt sensor for a tilt-enabled bike according to the present disclosure. 
         FIG. 34  shows a linear potentiometer tilt sensor for a tilt-enabled bike according to the present disclosure. 
         FIG. 35  shows a block diagram of a console in accordance with some embodiments of the exercise bike according to the present disclosure. 
     
    
    
     The drawings are not necessarily to scale. In certain instances, details unnecessary for understanding the disclosure or rendering other details difficult to perceive may have been omitted. In the appended drawings, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. The claimed subject matter is not necessarily limited to the particular examples or arrangements illustrated herein. 
     DETAILED DESCRIPTION 
     The present disclosure pertains to a stationary bike which is adapted to operate in a tilt-enabled (or tilting) mode in which a portion of the bike frame moves (e.g., tilts) relative to another, fixed portion of the frame. As such, a bike according to the present disclosure may be referred to as a tilt-enabled bike or simply tilting bike. The tilt-enabled bike is equipped with a locking mechanism that re-configures the tilt-enabled stationary bike to a non-tilting (or fixed) bike. In some embodiments, the locking mechanism may include a movable locking member supported on either the moving frame or the fixed frame(s) and selectively operable (e.g., movable) to a position in which the movable locking member engages a cooperating structure on the other one of the moving frame or the fixed frame(s) to interfere with the pivoting (or tilting) of the moving frame thus reconfiguring the bike into a fixed stationary bike. 
     With reference to  FIGS. 1 and 2 , a stationary (exercise) bike  10  according to the present disclosure may include one or more frame(s)  102  which operatively support the various moving components of the bike  10 . The one or more frame(s)  102  may include one or more first frame portion(s)  110 , also referred to as stationary or fixed frame(s)  110 , configured to remain substantially stationary during use of the bike  10 , whether the bike is in tilt-enabled or tilt-disabled mode. In some embodiments, stationary frame(s)  110  may be configured to be placed, and thus to support the bike  10 , on a support surface (e.g., on the ground). The one or more frame(s)  102  may also include a second frame portion  120 , interchangeably referred to as a moving, pivoting, or tilting frame  120 . The moving frame  120  is movably (e.g., pivotally) coupled to the one or more fixed frame portions  110  at one or more (e.g., two) pivot locations to enable the moving frame  120  and any components of the stationary bike that are carried on the moving frame, such as the seat  12 , crank wheel  22 , flywheel  29 , and pedals  32 , to move (e.g., pivot, tilt, or roll) with the moving frame  120  about a pivot or tilt axis A. 
     The stationary frame  110  may define two mounting locations, a front mounting location  103 - 1  and a rear mounting location  103 - 2 , at which the moving frame  120  is movably mounted (or suspended) on the stationary frame  110 . The mounting locations may define the tilt axis A. In other embodiments, the moving frame  120  may be pivotally mounted on the stationary frame  110  using a different number of mounting locations, for example a single mounting location (e.g., on a single pivot axis), which may define the pivot axis A of the bike. Any suitable pivotal joint that allows the moving frame  120  to pivot, with or without resistance, relative to the fixed frame  110  may be used to pivotally mount the moving frame  120  to the stationary frame  110 , e.g., at the mounting locations  103 - 1  and  103 - 2 . 
     The stationary frame  110  may include a front stabilizer  112 - 1  and rear stabilizer  112 - 2 , such as a pair of spaced apart transverse beams. The front and rear stabilizers may be implemented using a generally straight transversely extending beams or may any have other suitable geometry that provides a stable base for the bike  10 . The front stabilizer  112 - 1  and the rear stabilizer  112 - 2  support upwardly extending frame members (e.g., a front frame section  104  and a rear frame section  106 ) that pivotally support the moving frame  120  at respective front and rear mounting locations  103 - 1  and  103 - 2 . The front frame section  104  may define the front mounting location  103 - 1  at a vertical position below the rear mounting location  103 - 2  defined by the rear frame section  106 , such that the tilt axis A is inclined to the horizontal (e.g., ground  7 ) with the front end of the tilt axis A located closer to the ground  7 . In other examples, the front and rear frame sections may be differently configured, for example to define a tilt axis that is substantially parallel to the horizontal or inclined in the opposite direction (i.e., with the rear end of the tilt axis closer to the ground). In yet other examples, the fixed frame  110  may include a plurality of fixed frame portions, such as a front fixed frame and a rear fixed frame that may not be connected to one another. In some embodiments, the fixed frame  110  may be arranged at the front or the rear end of the bike and be configured to support and suspend the moving frame  120  via only a single pivot (e.g., a front pivot or a rear pivot). Other arrangements may be used in other embodiments. 
     Referring to the example in  FIGS. 1 and 2 , the front frame section  104  may include one or more frame members (e.g., tube  105 ), extending upward and/or rearward of the front stabilizer  112 - 1 . The front frame section  104  may include an upright mount  101  fixed and extending upward from the front stabilizer  112 - 1  and a tube  105  fixed to and extending rearward from the mount  101 . The terms “fixed” or “fixedly mounted” imply a connection between components that is intended to be non-movable when the bike  10  is in use. The front frame section  104  pivotally supports the front end  121 - 1  of the moving frame  120  as will be further described. The rear frame section  106  may include one or more frame members (e.g., curved tube  107 ), extending upward and/or forward of the rear stabilizer  112 - 2 . Additionally and optionally, the fixed frame  110  may include one or more longitudinal frame members (e.g., longitudinal beam  108 ) that extend between the front and rear stabilizers and/or the front and rear frame sections to connect the front frame section  104  to the rear frame section  106 , shown here as a curved tube  107 . While one or more of the frame members of the bike  10  are described as tubes or tubular members, any type of structural member that can carry the relevant loads (e.g., tension, compression, bending, and shear loads) may be used for implementing the frame of the bike  10 . For example, any of the tubular members of the frame may be replaced with a beam having a different cross section, which may not be an enclosed section, such as a U-shaped, T-shaped, I-shaped or differently shaped beam. Moreover, the term tube or tubular member does not necessarily imply a cylindrical tube but may include tubes having other transverse cross-sections such as rectangular, oval, triangular or other regular or irregular cross-sectional geometries. 
     To enable a user to perform exercise which simulates cycling, the bike  10  may include a seat  12  to support the user in a seated position, a handlebar to support a portion of the user&#39;s upper body (e.g., the user&#39;s hands and/or forearms), and a drive assembly  20  including a pair of pedals  32  configured to support and guide the user&#39;s feet in a cyclical motion. The moving frame  120  may include a front post or tube  44  that supports the handlebar  42 . In some examples, the handlebar  42  may be adjustably coupled to the front post or tube  44 . For example, the handlebar  42  may be coupled to a handlebar post  46  selectively movably received in the front tube  44  for adjusting the vertical position of the handlebar  42 . In other examples, the handlebar  42  may, alternatively or additionally, be adjustable in a different direction (e.g., horizontally). In yet other examples, the position of the handlebar  42  on the moving frame  120  may be fixed, such as by being rigidly coupled to the front post or tube  44 . Regardless of whether the handlebar  42  is fixed or adjustably coupled to the front tube  44 , the handlebar  42  may remain stationary with respect to the moving frame  120  when the moving frame  120  pivots in relation to the fixed frame  110 . In some embodiments, the handlebar  42  may be coupled to the moving frame  120  such that it is movable (e.g., pivotable about the axial direction of the tube  44 ) independently of or dependently upon movement of the moving frame  120 ). 
     The moving frame  120  may also include a rear post or tube  64 , which supports the seat  12  and may thus also be referred to as seat tube  64 . In some embodiments, the seat  12  is adjustable relative to the rear post or tube  64 . For example, the seat  12  may be coupled, in some cases adjustably, to a seat post  14 , which is coupled, in some cases also adjustably, to the rear post or tube  64 . The front post  44  and the rear post  64  may be suitably spaced apart (e.g., by center or top tube  48 ) to accommodate a human user in a seated position. In the illustrated example, the center tube  48  extends between the front tube  44  and the rear tube  64 , with the front and rear tubes  44  and  64 , respectively, being fixed to opposite ends of the center tube  48 . The handlebar  42  and/or the seat  12  may be adjustable relative to other components of the moving frame  120  (e.g., relative to the center tube  48 ) so as to further tailor the seated position provided on the moving frame to a particular user. 
     The drive assembly  20  may include a crankshaft  24  rotatably supported on the moving frame  120 . Left and right crank arms  26  may be fixed to opposite ends of the crankshaft  24 . The crank arms  26  may extending generally transverse to, and in radially opposite directions from, the crankshaft  24 . A pedal  32  is pivotally coupled at the terminal end of each crank arm  26  and configured for engagement by a user&#39;s foot. In some embodiments, the crank wheel  22  may be fixed to the crankshaft  24  such that the crank wheel  22  rotates synchronously with the crankshaft  24 . The rotation of the crankshaft  24  may be resisted by a resistance mechanism  30 , such as a frictionally-resisted or magnetically-resisted flywheel  29 . The resistance mechanism  30  may be operatively associated with the crankshaft  24 , for example by one or more transmission elements  28  (e.g., a belt or chain), operatively connecting the crank wheel  22  to the rotation axis of the flywheel  29  such that the resistance to rotation of the flywheel is transmitted to the crank wheel  22  and thus to the crankshaft  34  and pedals  32 . Like other stationary bikes, the resistance to rotation of the pedals  32  may be adjustable, for example via resistance knob  25  operatively engaged with the brake mechanism (e.g., a magnetic brake, such as an eddy current brake, or a friction brake) associated with the flywheel  29  to enable the user to increase or decrease the resistance to rotation applied to the flywheel  29 . 
     The moving frame  120  may be implemented using any suitable combination of structural members that can carry the loads applied thereto, such as by the user and the movable components of the bike  10 . For example as shown in  FIGS. 1, 2 and 4A , the moving frame  120  may include a rearwardly extending frame member, shown here as a rear fork  122  that extends generally rearward of the rear tube  64 . The rear fork  122  may include first (e.g., left) and second (e.g., right) rear fork members  122 - 1  and  122 - 2 , each of which extends from the rear tube  64  toward the rear end of the bike along an opposite side of the flywheel  29 , such that the rear fork  122  straddles the flywheel  29 . A front fork  124  may be fixed to and extend generally downward from the top tube  48 . The front fork  124  may similarly have a first (e.g., left) front fork member  124 - 1  and second (e.g., right) front fork members  124 - 2  that extend on opposite sides of the bike  10 . The front fork  124  extends to and is fixed to the lower end of the rear tube  64 , thereafter curving upward and extending rearward towards the rear end of the rear fork  122 . The respective sides of the front and rear forks may be connected to provide a support (e.g., a mount) for the flywheel  29 , which in this example is also carried on the moving frame  120 . In other examples, the moving frame may be differently configured. For example, a rearwardly extending frame member of the moving frame  120 , which supports the flywheel, may extend only along one side of the mid-plane of the bike (e.g., along the right side or the left side), and the flywheel  29  may be supported on a cantilevered shaft off the rearwardly extending frame member. Similarly, a front portion of the moving frame  120  may include one or more downwardly and/or forwardly extending frame members that is substantially centrally located (e.g., along the mid-plane) or which extend along only one side of the mid-plane of the bike. In the illustrated example, the free ends of the left front fork member  124 - 1  and the left rear fork member  122 - 1  are connected via a left flywheel mount, shown here as left plate  126 - 1 , and the free ends of the right front fork member  124 - 4  and the right rear fork member  122 - 2  are connected via a right flywheel mount, shown here as right plate  126 - 2 . A flywheel shaft  127  may extend between the left and right flywheel mounts (e.g., between the left and right plates  126 - 1  and  126 - 2 , respectively) to rotatably support the flywheel  29 . The flywheel shaft  127  may be rotatably coupled to the frame  120  via one or more one-way bearings  129  to transmit the rotation of the pedals in only one direction. Rotation of the flywheel thus remains unaffected when the pedals are rotated in the opposite direction and/or not rotated at all. 
     The tilting portion of the bike (e.g., moving frame  120  and components carried on the moving frame  120 ), may be mounted on the fixed frame  110  via a pair of spaced-apart pivot joints. Focusing on  FIGS. 2 and 5 , a first (or front) pivot joint  130  may be located at the front mounting location  103 - 1  and a second (or rear) pivot joint  160  may be located at the rear mounting location  103 - 2 , which suspends the moving portion of the bike  10  onto the fixed frame  110  allowing it to pivot (or tilt or roll) about the tilt axis A. Referring also to  FIG. 6A , the rear pivot joint  160  may be implemented using a rear pivot shaft  162 , which is joined to a rear portion  163  of the moving frame  120  and rotatably coupled (e.g., using one or more bearings  165 ) to a tubular housing  164  fixed to the rear frame section  106 . In other examples, this arrangement may be reversed. In other words, the rear pivot shaft  162  may be fixed to the fixed frame  110  (e.g., to the rear frame section  106 ) and may be rotatably received in a tubular housing of the moving frame  120 . 
     With reference to  FIGS. 5 and 6B , the front pivot joint  130  may be implemented using a front pivot shaft  132  fixed to the moving frame  120  and rotatably received (e.g., via one or more bearings  135 ) within a tubular housing  134  fixed to the stationary frame  110 . Similar to the rear pivot, the location of the front pivot shaft and housing that rotatably receives the front pivot shaft may be reversed as between the moving and stationary frames. Any other suitable pivot joint may be used to pivotally couple the front and rear portions of the moving frame to respective front and rear portions of the fixed frame to suspend the bike in space allowing it to pivot, with or without resistance, about a tilt axis connecting the two mounting locations. 
     In the specific illustrated example, the tubular housing  134  associated with the front pivot joint  130  is fixed to an upward extension  109  of the longitudinal beam  108  that connects the front and rear frame sections  104 ,  106 , respectively. The upward extension  109  is inclined to horizontal (e.g., to the horizontal plane defined by the front and rear stabilizers) at an angle that substantially matches the incline of the front fork  124  such that the upward extension  109  and the front portion of the front fork  124  are substantially parallel to one another. The front pivot shaft  132  may be joined to and extend from (e.g., substantially perpendicularly to) the front fork  124  toward the upward extension  109 . In other examples, this may be reversed and the front pivot shaft  134  may instead be fixed to the fixed frame  110  and rotatably coupled to a component on the moving frame  120 . 
     In some embodiments, the bike  10  may include a tilt measurement apparatus  400 . The tilt measurement apparatus  400  may include a sensor  410  operatively engaged with the moving frame  120  to measure the amount of tilt (e.g., a tilt angle, which corresponds to the angle between the plane M of the moving frame (also referred to as moving plane M) when the moving frame is in any given tilted position and the plane S of the fixed frame (also referred to a fixed plane)). In some examples, the sensor  410  may be a magnetic rotary position sensor, which may be fixed to the fixed frame  110  (e.g., carried on a sensor board mounted to the fixed frame  110 ). A magnet (not shown) may be fixed to the moving frame  120 , for example to the front pivot shaft  132 , e.g., at a location in front of the upward extension  109  such as at a forward most end of the front pivot shaft  132 . The magnet, which is fixed in a predetermined orientation with respect to the moving frame, for example in an orientation that aligns its N-S direction to lie within or perpendicular to the moving plane M, would thereby rotate in synchrony with the shaft  132 . As the moving frame  120  tilts out of the fixed plane S, the change in the magnetic field orientation generated by the magnet is measured by the sensor  410  to determine the tilt angle, i.e. the angle between the moving plane M and the fixed plane S. Other types of sensors may be used in other examples, such as, and without limitation, a coded wheel, an optical interrupt sensor, a rotary potentiometer (non-magnetic), accelerometer, gyro, a linear potentiometer, or combinations thereof. 
     In other embodiments, the tilt sensor  410  may be implemented using a coded wheel sensor arrangement, as shown for example in  FIGS. 33A and 33B . The sensor arrangement  500  includes a wheel  510  mounted to one of the fixed frame or the moving frame, and a sensor board  520  mounted to the other one of the fixed frame and the moving frame. In this example, the sensor board  520  is mounted on the fixed frame and the wheel  510  is mounted to the moving frame, and more specifically to front pivot shaft  132 . In other examples, the wheel  510  may be associated with another one of the pivot shafts (e.g., rear pivot shaft  162 ), or may instead be mounted to the fixed frame while the board  520  is mounted to the moving frame. 
     The wheel  510  defines a plurality of coded positions  512  arranged at different radial locations along the wheel, each of the coded positions operable to activate or deactivate a switch when aligned therewith. The wheel  510  is shown here as relatively rigid plate that spans only that portion of a full wheel or circle that encompasses the tilt range of the bike. In other embodiments, the wheel  510  may be differently configured (e.g., having a different shape and/or positioning with respect to the pivot shaft  132  such as by extending in a different radial direction therefrom. The sensor board  520  includes a plurality of switches  522  which can interact with the coded positions on the wheel  510  to be switched between an ON state and an OFF state. In some examples, the switches  522  may be contact switches, which turn ON or OFF upon contact with a respective one of the coded positions  512 . In other examples, the coded wheel  510  may define a plurality of windows which activate or deactivate photo interrupt switches. Various other types of switches may be used. The plurality of switches  522  may be arranged in a line that extends radially from the pivot axis A. For example, the switches  522  may be arranged to lie in the plane with respect to which rotational displacement (or tilt) is being measured, in this case the switches lie in the fixed plane S. The coded positions  512  on the wheel  510  may be arranged along the surface of the wheel  510  that faces the switches  522  in an array that results in an unique combination of switches  522  being activated at any given rotational position, and thus at any given tilt angle, of the front pivot shaft  132  with respect to the fixed frame. As such, the wheel  510  is configured to a unique angular position switch code at any given angular position of the wheel  510  with respect to the line of switches  522 . 
     As an example, and referring also to  FIG. 33B , the wheel  510  may include 4 rows of coded positions  512 , referred to for the purposes of this explanation as switch windows but not necessarily to imply a through passage. The first row of coded positions includes 8 coded positions or windows  512 - 1  equally spaced from one another by a first distance, which may be substantially equal to the width of each window  512 - 1 . The second row has 4 coded positions or windows  512 - 2 , which are wider than the first windows  512 - 1 . Each of the second windows  512 - 2  is about twice the width of a first window, the second windows being spaced from one another by a second distance greater than the first distance (e.g., a distance substantially equal to the width of the second windows  512 - 2 ). The third row has two coded positions or windows  512 - 3 , each of which is about twice the width of a second window  512 - 2  and which are spaced apart by a third distance greater than the second distance (e.g., a spacing distance equal to about twice the width of the third window  512 - 3 ). The fourth row includes a single coded position or window  512 - 4  having a width of about twice the width of a third window  512 - 3 . The first coded position in each row are aligned in the radial direction, with the rest of the coded positions being arranged, based upon the above described relationships, in a manner that defines at least 16 unique combinations of active/inactive switches and thus  16  uniquely discernable rotational positions  513 , as shown in the switch code table  515 . As such, one of 16 unique rotational of tilt angle values may be determined based upon the unique switch combination output by the coded wheel sensor. In the specific example in  FIG. 33B , the coded wheel  510  is oriented in relation to the line of switches (e.g., switches  522 - 1  through  522 - 4 ) such that the first, second, and third switches ( 522 - 1  through  522 - 3 ) do not align with a coded position and thus, in this example, register as inactive (or OFF state with a switch value of 0), while the fourth switch  522 - 4  is aligned with a coded position, shown here as overlapping a portion of the fourth window  512 - 4 , and thus registering as active (or ON state with a switch value of 1). This coded position may be used to designate the nominal (or un-tilted) state of the bike. The number and arrangement of coded positions on the wheel  510  in this example is provided for illustration only and any other suitable combination, including a different (e.g., greater or fewer) number of coded positions in different arrangements along the face of the wheel  510  may be used to achieve any desired number of unique switch combinations 
     In another embodiment, the tilt sensor  410  may be implemented using a linear potentiometer type sensor, an example of which is shown in  FIG. 34 . In this example, the linear potentiometer is implemented using a rotating arm linkage  550  operatively coupled to the moving frame  120 . The rotating arm linkage  550  includes a first link  552  fixed to and extending radially from the pivot shaft  132  such that the radial end of the link  552  pivots about the axis of the shaft  132  in synchrony with the shaft  132 . A second link  554  optionally connects the radial end of the first link to a linear potentiometer type sensor  558  (e.g., a slide pot). For example, a second link  554  may be connected to the radial end of the first link  552  such that the second link  554  swings along an arc defined by the radial end of the first link  552  as the first link  552  pivots with rotation of the shaft  132 . The free end of the second link  554  is operatively engaged with a linear potentiometer type sensor  558  (e.g., a slide pot). In other embodiments, the radial end  553  may be operatively engaged with the linear potentiometer  558  in a different manner, e.g., by directly and/or compliantly coupling the radial end  553  to the linear potentiometer  558 . 
     Referring back to  FIGS. 4A, 4B, and 5 , the tilt-enabled bike  10  may be equipped with a locking mechanism  200  operatively arranged to convert the bike  10  from a tilting stationary bike to a non-tilting (or fixed) stationary bike, and vice versa. The locking mechanism  200  may be operatively associated with an actuator  300 , such as the actuator  301  shown for example in  FIGS. 7A, 7B, and 8A , the actuator  321  shown for example in  FIGS. 7C, 7D and 8B , or another suitable actuator. The actuator  300  may be configured for local or remote actuation or activation to engage and disengage the locking mechanism  200 . In use, when the locking mechanism  200  is disengaged, the bike  10  is operable to tilt or lean from side to side.  FIG. 4A  shows the bike  10  in neutral (or non-tilted) state or position, in which the mid-plane M of the moving portion of the bike  10  (e.g., moving frame  120 ) is substantially aligned with the mid-plane S of the fixed frame  110 . In a tilted state or position, e.g., as shown in  FIG. 4B , the mid-plane M of the moving portion of the bike  10  is at an angle to the mid-plane S of the fixed frame  110 . The angle between the two planes M and S may be referred to as the lean or tilt angle. 
     The maximum tilt or lean angle of the bike  10  may be limited by any suitable mechanism, such as a hard-stop and/or a damper. The damper may be implemented using any suitable mechanism that can provide resistance, and in some cases providing variable resistance, to the rotation of the moving frame relative to the fixed frame. In some examples, the damper may be implemented using one or more springs or other suitable resistance mechanisms (e.g., a shock tube) that can resist the movement of the moving frame. 
     When the locking mechanism  200  is engaged, pivoting of the moving frame  120  relative to the fixed frame  110  may be substantially prevented, allowing the user to operate the bike in a more conventional manner (without lean). Conventional, non-leaning/tilting bikes, may experience some nominal amount of lateral (side to side) movement of the frame, which naturally occurs due to the forces applied by the user on the frame when performing strenuous exercise. In such conventional stationary bikes, however, there isn&#39;t a distinct portion of the frame that is intended to move relative to other portions of the frame but instead the frame members are intended to remain generally fixed in relation to one another during use of the bike. As such, nominal side to side movement of a conventional bike frame is not what is being described here as the tilting or relative movement of a moving frame  120  to a fixed frame  110  of a tilt-enabled bike  10 . When operated in the tilt-disabled or fixed mode, the bike  10  is essentially locked into the nominal (or substantially vertical) position shown in  FIG. 4A . 
     In some embodiments, the pivoting (or tilting) movement of the bike  10  about the tilt axis A may be resisted by a damper  190  operatively engaged with the front pivot, the rear pivot or both. The damper  190  may include one or more resilient members arranged to be increasingly loaded as the tilt angle of the bike increases. In the present example, and referring also to  FIG. 23 , the damper  190  includes a pair of resilient members (or springs)  192 - 1  and  192 - 2 , each disposed on opposite side of the front pivot shaft  132 . The first spring  192 - 1  may be positioned proximate to a first side (e.g., a top side) of the front pivot shaft  132  and is thus above the tilt axis A, while a second spring  192 - 2  is positioned proximate a second opposite side (e.g., a bottom side) of the front pivot shaft  132 , such that the second spring  192 - 2  is below the tilt axis A. Each of the resilient members or spring  192 - 1  and  192 - 2  may be an elastomeric (e.g., rubber) tube. However, in other examples, the resilient members or springs  192 - 1  and  192 - 2  may be implemented using any suitable type of resilient member or spring, such as an elastomeric (e.g., rubber) cylinder, a helical spring, a leaf spring or the like. 
     In an arrangement of two springs on opposite sides of the pivot shaft, each spring acts to resist the rotation of the front pivot shaft  132  in one of the two rotational directions (i.e., clockwise as shown by arrow C or counterclockwise as shown by arrow CC). In other examples, two springs may be positioned on substantially the same side of the shaft, one of the springs acting in compression to resist rotation about one of the two rotational directions and the other spring acting in tension to resist rotation about the other one of the two rotational directions. In some examples a single spring may be configured to provide the resistance to rotation in both directions. Other suitable arrangements may be used for the damper. For example, in some embodiments, the resistance to tilt or lean of the bike may be provided by the locking mechanism  200 , which may be selectively operable to provide variable resistance to pivoting of the moving frame when not in a fully locked-out state and which may substantially prevent any tilt or lean when in the fully locked-out (or max resistance) state. In some embodiments, resistance to rotation of the pivot shaft may be applied by one or more resilient members positioned between the pivot shaft and the housing that rotatably received the shaft. The one or more resilient members may be positioned in one or more cavities or pockets between the pivot shaft and the housing such that the one or more resilient members are compressed during the rotation of the pivot shaft thereby resisting the rotation of the pivot shaft. 
     With continued reference to  FIG. 23 , each spring  192 - 1  and  192 - 2  is joined to either the fixed frame  110  or the moving frame  120 , and arranged to engage with, in this case in compression, the other one of the fixed or moving frame  110 ,  120  to provide resistance to pivoting of the moving frame  120  about the tilt axis A. The springs  192 - 1  and  192 - 2  are arranged between a pair of opposing and substantially parallel plates  194  and  196 , one of which (e.g., plate  194 ) is fixed to the fixed frame  110  and the other (e.g., plate  196 ) to the moving frame  120 . In the present example, both springs  192 - 1  and  192 - 2  are fixed to the fixed frame  110  by being fixed to a first plate  194  (also referred to as fixed plate  194 ). The fixed plate  194  is rigidly coupled to the upward extension  109  and is oriented with its major surfaces substantially parallel to the tilt axis A. The second plate  196  is fixed to the moving frame (and thus also referred to as moving plate  196 ). More specifically, the second plate  196  here is rigidly coupled to the front fork  124  of the moving frame  120 . The second plate  196  is similarly oriented with its major surfaces substantially parallel to the tilt axis A. As the bike tilts in one direction (e.g., clockwise), the moving plate  196  engages (e.g., compresses) one of the springs (e.g., first spring  192 - 1 ) and as the bike tilts in the opposite direction (e.g., counterclockwise, the moving plate  196  engages (e.g., compresses) the other one (e.g., the second spring  192 - 2 ). 
     In other examples, a different arrangement and/or operation of the springs may be used. For example one of the springs may be fixed to the fixed plate, while the other may be fixed to the moving plate. In some examples, such as the one illustrated in  FIG. 23 , each of the springs may have one of its ends fixed to a plate, while the opposite end of each spring is not fixed to a plate. In this manner, each spring may act only in one direction (e.g., in compression). In other examples, both ends of a spring may be fixed to a respective one of the fixed and moving plates, such that the spring may both compress when the bike is tilting in one direction and extend when the bike is tilting in another direction. In some such embodiments, one of the directions (when compressing or when extending) may be consider a primary or active direction and the other may not significantly impact the damping performance of the damper  190 . In some cases, the springs may be configured such that both directions are considered active and contribute to the damping provided by damper  190 . 
     In some embodiments, the resistance to pivoting may be adjustable, for example by varying the stiffness of the spring, which can be achieved by increasing a pre-load on the spring in the nominal (un-tilted) position. In some embodiments the resistance to pivoting may be adjusted by engaging a select number of a plurality of different resistance elements (e.g., springs). In the example illustrated in  FIG. 23 , variable resistance is achieved by selectively adjusting the engagement surface that engages the free end of each of the springs. In this case, respective cups  198 - 1  and  198 - 2  are adjustably (e.g., via a respective screw  199 ) coupled to the engagement side of the moving plate  196  at a location to engage the free end of the respective spring  192 - 1  and  192 - 2 . Each cup receives the free-end of the spring during engagement. Each cup can be selectively positioned (by loosening and tightening of the respective screw) closer to the moving plate  196  and thus farther from the respective spring to decrease the spring&#39;s preload or farther away from the moving plate  196  and thus closer to the respective spring to increase the spring&#39;s preload. 
     Other variations and combinations of elements may be used to effectively implement a damper that resists the rotation of the pivot shaft  132 . Also, while described here with reference to the front pivot, a similar or other suitable damper may be provided at the rear pivot instead or in combination with resistance at the front pivot. 
     Returning back to  FIG. 5  and referring now also to  FIGS. 7A, 7B, 7C, 7D, 8A, and 8B , the tilt-enabled bike  10  may be equipped with a locking mechanism  200  operatively arranged to convert the bike  10  from a tilting bike mode to a non-tilting (or fixed) bike mode, and vice versa. The locking mechanism  200  may be operatively associated with an actuator  300 , which may be configured for local or remote actuation (or activation) to engage and disengage the locking mechanism  200 . For example, the actuator  300  may be implemented by actuator  301 , actuator  321  or another suitable actuator. The locking mechanism  200  may be implemented using any suitable mechanism capable of substantially eliminating (or locking out) the relative movement between the moving frame  120  and the fixed frame  110 , thereby converting the tilting bike  10  into a non-tilting (or fixed) bike. 
     Any suitable locking mechanism that disables the tilting function of the bike  10  may be used. The various locking mechanisms may generally be characterized as falling in one of two categories, e.g., mechanisms that act on and interfere with the rotation of the pivot shaft of the at least one pivot joint that pivotally couples the moving frame  120  to the fixed frame  110 , and mechanisms that mechanically interfere with the relative movement between the moving and the fixed frames. In the former category, exemplary tilt-disabling mechanisms may include various types of friction brakes that engage the pivot shaft to resist and/or prevent its rotation. Some of these mechanisms may provide variable resistance, which may be used to resist the pivoting movement of the moving frame (e.g., in place of a damper) and the resistance may be increasable up to a setting in which the rotation of the pivot shaft is substantially fully constrained, thus locking out the tilt function of the bike. The latter category of mechanisms may include various arrangements of pins or blocks that are movable between two positions including a position, in which the pin or block does not interfere with the movement of the moving frame, and another position, in which the pin or block interferes with the movement of the moving frame. 
     Examples of a locking mechanism  200  are illustrated in  FIGS. 7A-7D , which show a tilt-lock assembly  600  of the bike  10  in a disengaged (unlocked) state (in  FIGS. 7A and 7C ) and an engaged (locked) state (in  FIGS. 7B and 7D ). The tilt-lock assembly  600  may include a locking mechanism  200  and an actuator (e.g., actuator  301  in  FIGS. 7A and 7B , and actuator  321  in  FIGS. 7C and 7D ). In these examples, the tilt-lock assembly  600  is configured for manual, and thus local, actuation. The terms local and remote, when describing the actuation of the locking mechanism, refer to actuation controlled by a device co-located with the locking mechanism (e.g., on the bike itself), and actuation controlled by a device removable or disconnected from the bike (e.g., an electronic device such as a smart phone or tablet), respectively. The locking mechanism  200  in the present examples includes a lock block  210  movably (in this case pivotally) mounted to the moving frame  120 , and configured to mechanically engage a locking feature  225 , which may be a portion of the fixed frame  110 . In the present example, the locking feature  255  may be a protrusion  230  fixed to the frame  110 . Mechanical engagement of the lock block  210  with the locking feature  225  prevents the relative movement of the moving frame  120  with respect to the fixed frame  110 . The term mechanically engage implies physical contact between the specified components when they are said to be mechanically engaged. 
     Referring to  FIGS. 7A, 7B, 7C, 7D, 8A and 8B , the lock block  210  is pivotally mounted to the moving frame  120 , e.g., via a pin  242  and one or more bearings  244 . In this example, the pin  242  is coupled to the moving frame  120 , extending generally transverse to the top tube  48 . Two bearings  244  are positioned at the opposite ends of the pin  242  and support opposite sides of the lock block  210 . The one or more bearings  244  rotatably couple the lock block  210  to the pin  242  such that the lock block  210  pivots about a lock block pivot axis B, which is also the axis of the pin  242 . The lock block  210  has a length L, which is the distance defined between its opposite side walls  211 - 1  and  211 - 2 , and is arranged such that the length L is oriented substantially along the axis B. The lock block  210  has an engagement portion  213  and an actuation portion  215  provided generally on opposite sides of the axis B. The engagement portion  213  includes a peripheral wall  214 , which extends between the opposing side walls  211 - 1  and  211 - 2  and defines an engagement groove  212 . The engagement groove  212  extends from the peripheral wall  214  radially inward toward the axis B. The actuation portion  215  includes a substantially rigid lever  217  extending from a peripheral location of the actuation portion  215  radially inward toward the axis B. The peripheral end of the lever  217  is coupled to the actuator of the tilt-lock assembly  600  (e.g., actuator  301  in  FIGS. 7A and 7B  or actuator  321  in  FIGS. 7C and 7D ) such that an actuation force may be applied on the lever  217  to pivot the lock block  210  about axis B. 
     The engagement groove  212  is configured to receive at least a portion of the lock feature  225 , such as a protrusion  230  or the like, that is rigidly mounted on the fixed frame  110 . The groove  212  may be tapered such that its width reduces farther away from the protrusion. The protrusion  230  may be correspondingly tapered. For example, the upper portion of the protrusion  230 , which is closer to the block  210  and thus to the groove  212 , may be narrower than portions of the protrusion  230  farther away from the block  210  and thus the groove  212 . Stated differently, the opening of the groove  212 . which is the part of the groove  212  that is closest to the protrusion  230 , has a generally larger size (e.g., is wider) than the size of the groove  212  farther away from the protrusion  230 . Similarly, the protrusion  230  is narrower at its free end than at its base. Referring also to  FIGS. 9A-C  and  FIGS. 10A-C , which show the lock block and protrusion at three different states including a disengaged state ( FIGS. 9A and 10A ), an engaged state ( 9 C and  10 C), and a partially engaged state ( 9 B and  10 B), the tapering of the groove  212  and protrusion  230  may facilitate engagement between the groove  212  and protrusion  230  without precise alignment of the two. The tapering may provide a self-centering function as the user operates the locking mechanism into engagement with the groove. For example, as shown in  FIGS. 9B and 10B , as the moving frame and thus the block  210  tilts off center (i.e., out of the stationary plane S), the size of the groove&#39;s opening  219  being larger than the upper portion of the protrusion may facilitated insertion of the protrusion into the groove as the bike tilts back to center. In some examples, the groove  212  may be tapered in one direction (e.g., its depth direction) or in two directions (e.g., along its depth and length directions). In the illustrated example, the groove  212  is tapered along its length in that the shape of the aperture in the peripheral wall  214  that defines the opening  219  of the groove has a substantially trapezoidal shape (e.g., as seen in  FIGS. 8A and 8B ). In addition, the groove  212  is tapered along its depth, the width W of the groove  212  narrowing from the opening  219  in the radially inward direction (i.e. toward the axis B). The shape of the protrusion  230  may correspond to that of the groove  212  and thus the protrusion  230  may also be tapered in one or multiple directions. Such a tapered protrusion  230  may thus also be referred to as a tapered pin or a wedge  230 . 
     In some embodiments, the groove  212  and the wedge  230  may be sized for a transition fit, implying only negligible, if any, clearance between the interfacing surfaces of the groove  212  and wedge  230  so as to provide a tight fit without substantially any free play. In some embodiments, the lock block  210  or at least the engagement portion  213  thereof, may be made from a durable rubber material (e.g., rubber having Shore A hardness of 80, 85, 90 or greater), while the wedge  230  may be made from a substantially rigid material, such as metal, plastic, or rigid composite, which in combination with the taper of the two components may facilitate a tightly fitting mechanical engagement between the two. In other embodiments, the wedge  230  (e.g., at least the portion thereof that engages the lock block) may instead be made from durable rubber, while the lock block  210 , or at least the engagement portion thereof, is substantially rigid (e.g., metal, plastic, or a rigid composite). In some examples, the groove  212  and protrusion  230  may be differently shaped, e.g. non-tapered or tapered to a higher degree, such as up to a taper angle of about 140 degrees (see e.g.,  FIG. 10C ), in one direction such as the length direction, or in some cases in both directions. 
     The length L of the lock block  210  may be sufficiently large to ensure that as the bike leans from side to side, at least a portion of the block  210  remains over the protrusion  230 , as shown for example in  FIGS. 9B and 10B , in which the moving frame is tilted and thus the block  210  is off center with respect to the fixed frame and the protrusion  230 . However, the block  210  is sized so that even at the maximum lean of the bike, the side wall of the block, in this case the first wall  211 - 1 , does not clear the protrusion  230 . In such embodiments, the length L of the block  210  may be about half of the length of the tilt arc through which the moving frame  120  may be configured to pivot. 
     The tilt-lock assembly  600  may include an actuator  300  to pivot the lock block  210 , some examples of which are illustrated in  FIGS. 7A-D  and  8 A and  8 B. Referring to  FIGS. 7A, 7B and 8A , the actuator  301  may be implemented as a rod assembly, or rod,  302 , which is arranged such that the length of the rod  302  is substantially perpendicular to the axis B. One end  303  of the rod assembly  302  is coupled to the lever  217  of the lock block  210  and the opposite end  304  of the rod assembly  302 , which may be referred to as the manipulation end  304 , is provided at an accessible location on the bike (e.g., a location which is not hidden behind protective shrouding). In some embodiments, the manipulation end  304  may be provided at a location which is accessible to the user while riding the bike  10 , such as proximate to the resistance knob  25 . 
     The rod assembly  302  includes a housing  310  and a plunger  314  at least partially and movably received in the housing  310 . In some embodiments, for the ease of assembly/installation of internal components of the rod assembly  302 , the housing  310  may be manufactured as a multi-part component including a first (or main) housing portion  310 - 1 , a second (or intermediate) housing portion  310 - 2  and a third (or top) housing portion  310 - 3 , which are assembled together to provide the housing  310  of the rod assembly  302 . For example, the lower portion of the housing  310  may be manufactured in two parts to enable installation of one or more latching balls  318 . The upper portion of the housing  310  may be manufactured as yet another separate part (e.g., the top housing portion  310 - 3 ) to enable installation of the plunger  314 , within the passage  309  defined by the housing  310 . The plunger  314  may be sized to be received within the passage  309  and may be biasingly connected (e.g., via a spring  316 ) to the housing  310 . In some embodiments, the rod assembly  302  may be compliantly coupled to the lock block  210  to facilitate locking of the actuator in the engaged position even when the bike is off-center. In the illustrated example, the rod assembly  302  is compliantly coupled to the lock block  210  via a spring  312 , which connects the housing  310  of the rod assembly  302  to the lever  217  of the lock block  210 . The spring  312  may be a coil spring, a resilient member (e.g., a rubber rod or other suitable elastic elongate member) or any other suitable elastically deformable body. 
     To operate the tilt-lock assembly  600 , the user pulls the manipulation end  304  of the rod assembly  302 , and more specifically the plunger  314 , upward in the direction  602  in  FIG. 7A , which by virtue of the connection between the plunger  314  and the housing  310  causes the housing  310  to displace upward (in the direction  602 ) as well. In some embodiments, in the which the rod assembly  302  is installed to sit substantially flush with the shroud  308  when disengaged, a pull loop or other feature may be operatively installed at the manipulation end  304  of the rod  302  to enable the user to pull on the rod  302 . As the plunger  314  and housing  310  move upward, the latching balls  318  move upward as well until they become elevationally aligned with the detent holes  319  in the sleeve  306 . The sleeve  306  may be provided by a downward extension of the shroud  308  that defines a passage sized to accommodate the rod assembly  302 . When so aligned, the balls  318  displace outward into the detent holes  319  in part due to the widened lower portion  315  of the plunger  314 . The latching balls  318 , and consequently the rest of the rod assembly  302 , are held in this upward extended position (shown in  FIG. 7B ), which corresponds to the engaged (or locked) position of the tilt-lock assembly, until the user operates the actuator  301  in reverse. When the plunger  314  and housing  310  are thus moved upward, the lock block  210  rotates in a first direction, shown by arrow  606 , to pivot the engagement portion  213  downward toward the fixed frame  110  to engage the locking feature of the fixed frame, in this case the wedge  230 . In other embodiments, the plunger  314  may be differently latched to the housing  310 , for example using one or more resilient members or other structures (e.g., tabs) that are biased outward by the plunger to prevent relative movement of the plunger and the whole rod assembly thereby locking the rod into position. 
     To deactivate or disengage the locking mechanism, the user simply pushes down on the rod assembly  302 , which causes the rod assembly  302  to move in the opposite, downward direction, as indicated by arrow  604  in  FIG. 7B . In response, the plunger  314 , and thus its widened portion  315 , moves down allowing the latching balls  318  to displace out of the detent holes  319  inward toward the centerline of the rod assembly  302 , de-latching the actuator  301  from the engaged position. The rod assembly  302  returns to its dis-engaged position, in this case seated against the recess  307  of the shroud  308 . The rod assembly  302  may return to its retracted position in part due to the downward user force and/or gravity, and in some case, when compliantly coupled (e.g., via a spring  312 ), in part also due to the spring force of spring  312 . When the rod assembly  302  is pushed down, the lock block  210  rotates in the opposite direction, indicated by arrow  608  causing the engagement portion  213  to rotate upward (as indicated by arrow  608 ) and away from the fixed frame  110  thereby disengaging from the locking feature  225  of the fixed frame  110  and unlocking the tilt-lock assembly  600  to enable the tilt mode of the bike  10 . 
       FIGS. 7C, 7D, and 8B  show actuator  321  in accordance with further examples herein. The actuator  321  may be implemented using a rod assembly, or rod,  322 . The rod assembly  322  may be arranged similarly to the rod assembly  302 . One end  323  of the rod assembly  322  is coupled to the lever  217  of the lock block  210 . An opposite, manipulation end  324  is provided in a location accessible to the user, similarly to the manipulation end  304  of rod assembly  302 , to allow the user to operate the actuator  321  for engaging and dis-engaging the tilt-lock assembly  600 . 
     The rod assembly  322  includes a housing  330  and a plunger  334 . The plunger  334  may be sized to be received within a passage  329  in the housing  330 . The plunger  334  interacts with a spring  336  and includes a widened lower portion  335  that interacts with latching balls  338  in a similar manner to rod assembly  302 . The rod assembly  322  may interact with a sleeve  326 , recess  327 , shroud  328 , and detent holes  339  in the sleeve  326 . Elements of the rod assembly  322  such as the manipulation end  324 , sleeve  326 , recess  327 , shroud  328 , passage  329 , housing  330 , plunger  334 , widened lower portion  335  of the plunger  334 , spring  336 , and latching balls  338  may be similar in features, manufacture, operation, and arrangement to analogous components of the actuator  301 , and their description, therefore, will not be repeated here. 
     Like the rod assembly  302 , the rod assembly  322  includes a spring  332 , which may be a coil spring or other elastically deformable member. In the rod assembly  322 , the spring  332  is configured as a compression spring, in that the spring  322  is compressed when the actuator  321  is in the engaged position. The spring  332  may be operatively associated with the housing  330  such that the spring  332  is loaded in compression when the actuator  321  is in the engaged position. For example, the rod assembly  322  may include a first elongated element  340  and a second elongated element  342  each of which engage an opposite side of the spring  332  to compress the spring  332  when the actuator  321  is in the engaged position. The first elongated element  340  is coupled to the housing using any suitable first coupling feature  344 - 1  (e.g., one or more hooks or loops). The first coupling feature  344 - 1  is provided at one end of an elongated body section  346  of the elongate element  340 , and a second coupling feature  344 - 2  (e.g., one or more hooks or loops) is provided at the opposite end of the elongated body section  346 . The housing  330  may include an axle or post  356  that couples the first coupling feature  344 - 1  to the housing, such as by being received in the hook or loop. The first coupling feature  344 - 1  may be configured to allow the elongated body section  346  to pivot about the axle  356 . The second coupling feature  344 - 2  are configured to engage a lower end  358  of the spring  332 . For example, hooks  348 - 1  and  348 - 2  may wrap under the lower end  358  of the spring  332 . 
     The second elongated element  342  is coupled to the lever  217 . For example, the second elongated element  342  may have a suitable coupling features  350 - 1  (e.g. a hook or loop) at one end of an elongated body section  352  of the elongate element  342 . Another coupling feature  350 - 2  (e.g., one or more hooks or loops) are provided on the opposite end of the elongated body section  352 . The coupling feature  350 - 1 , in the illustrated examples includes a loop, engaged with the lever to move the lock block  210  between the engaged and disengaged positions, in a manner similar to that of the operation of spring  312 . The coupling feature  350 - 2  on the opposite end of the elongate element  342  is configured to engage an upper end  360  of the spring  332  to apply compressive force to the spring when the actuator  321  is provided to the engaged position. For example, one or more hooks  354 - 1  and  354 - 2  may wrap over the upper end  360  of the spring  332 . The spring  332  is held between the first elongated element  340  and the second elongated element  342 . 
     The first and second elongated elements  340 ,  342  may be formed from any suitable material, for example suitably shaped wire(s), cable(s) (single or multi-strand), or a combination thereof. In some embodiments, the first and second elongated elements  340 ,  342  may be rigid links. In other embodiments, the first and second elongate elements  340  may be implemented using non-rigid members that can carry a load in tension, such as chain(s), strap(s), cords, or combinations thereof, which are operatively coupled to engage the spring loading it in compression. The first and second elongated elements  340 ,  342  may be made of any material of sufficient strength to compress the spring  332 . For example, the first and second elongated elements  340 ,  342  may be made of steel, plastics, or reinforced composites. The first and second elongated elements  340 ,  342  may be formed by extrusion (such as in the example of wires, that may be subsequently shaped to the desired final shape), they may be stamped, molded (such as in the example of a rigid link), or additively manufactured. 
     To engage the locking mechanism, via the rod assembly  322 , the user pulls up on the manipulation end  324  in the direction  602  as shown in  FIG. 7C . The rod assembly  322  differs from the rod assembly  302 , at least, in that the spring  332  is configured to be loaded in compression when the locking mechanism is engaged, rather than in tension as is the case in rod assembly  302 . As the housing  330  moves up, the axle  356  pulls up on the hook  344  of the first elongated element  340 , moving the elongated element  340  generally in the same direction as the housing  330 . This motion imparts a force to the lower end  358  of the spring  332  via the coupling feature  344 - 2 . This force is translated through the spring  332 , which compresses in the process, to the coupling feature  354  of the second elongated element  342  via the upper end  360  of the spring. The force is transferred via the elongated body section  351  to the lever  217  causing the lever  217  to rotate the lock block  210  to the locked position, as previously described. Due to the pivotal movement of the lock block  210  and lever  217 , the assembly of the first and second elongate members  340  and  342 , respectively and the spring, may pivot slightly within the housing  330  about axle  356 , as can be seen in  FIGS. 7C and 7D . In some embodiments, the housing  330  may be sized sufficiently large to accommodate this pivoting movement. In other embodiments, a length-wise slot may be formed in the lower portion of the housing g 330 , as can be seen in  FIG. 8B . To disengage the locking mechanism, the user pushes down on the rod assembly  322 , as previously described with respect to the rod assembly  302 . 
     By loading the spring  332  of the rod assembly  322  in compression in the engaged position, a more sturdy engagement of the lock block  210  with the opposing fixed feature of the bike frame may be achieved, which may reduce the risk of inadvertently (i.e., unintentionally) disengaging the locking mechanism while a user is riding the bike. Other solutions that may reduce the risk of accidentally disengaging the locking mechanism, such as when using a spring loaded in tension, may including using a spring of sufficient stiffness to substantially resist the torque that may be caused on the lock block due to side to side (or leaning) movement of the bike when the locking mechanism is engaged. Other suitable variations may be used. 
     The tilt-lock assemblies  600 ,  600 ′ may provide certain technical advantages. For example, when a user rides the bike  10 , a torque may be imparted on the lock block  210  in the direction  608  shown in  FIG. 7D  (toward an unlocked position) which may increase the risk of the lock block  210  inadvertently disengaging. By increasing the stiffness of an extension spring (but not exceeding a stiffness at which a normal user can actuate the rod assembly) or by loading the spring in compression, the risk of unintentionally disengaging the locking mechanism may be reduced or eliminated. 
     The locking mechanism may be configured to be provided in a partially engaged state, as shown in  FIGS. 9B and 10B . In this state, the actuator may be engaged (or locked into the engaged position), shown in  FIGS. 7B and 7D , while the lock block  210  may not be fully engaged with the protrusion  230 , for example because the lock block  210  is off center and thus the groove and protrusion are misaligned. In this state, as the user operates the actuator and locks it into engagement, the lock block  210  may be rotated downward in the direction  606  but instead of receiving the protrusion  230  within its groove  212 , a radially extending surface  216  of the lock block  210  may be brought into contact to rest against the interfacing side  232  of the protrusion  230 , which is similarly inclined to match the incline of the interfacing side  232  in this position. The actuator  300  is coupled at its lower end to the lock block  210  such that there is some amount of laterally compliance (e.g., due to the coupling via the spring  312  of actuator  301  or the spring assembly of actuator  321 ) and thus, as the moving frame and the block  210  return to center and the groove  212  begins to aligned with the protrusion, the spring force acting on the lever  217  pulls the lock block  210  info full engagement, as shown in  FIGS. 9C and 10C , in which the protrusion  230  is received at least partially within the groove  212  to constrain further tilting of the moving frame. 
     Features of the lock block  210  and cooperating protrusion  230  may be differently configured in other embodiments. For example, the taper of the lock block  210  may be greater than (e.g., up to a taper angle of about 140 degrees) or smaller (e.g., up to a taper of 0 degrees, or no taper, in which case the walls of the groove would be substantially parallel). When a narrower groove  212 , and especially when the groove  212  is substantially untapered, a more precise centering of the bike  10  may be needed by the user prior to engaging the locking mechanism. In contrast, the taper of the groove  212  may provide a centering function obviating the need for the user to precisely align the bike to center before engaging the tilt-lock assembly. The coupling between the actuator  300  and the lock block may provide lateral compliance or flexibility to allow locking of the actuator without centering of the bike, while reducing compliance or flexibility in the longitudinal direction while in the engaged position (e.g., by compression loading of the spring) to reduce unintentional disengaged of the locking mechanism. In other embodiments, the actuator  300  may not be compliantly coupled and may instead have a rigid link for its lower portion that is pivotally connected to the lever  217  of the lock block. 
     In some embodiments, the operation of the tilt-lock assembly may be reversed. For example,  FIGS. 11A and 11B  show a tilt-lock assembly  600 ′ which has similar components to those of tilt-lock assembly  600 . Specifically, the tilt-lock assembly  600 ′ includes an actuator  300 , which may be implemented using the actuator  301  and the rod assembly  302  described with reference to  FIGS. 7A, 7B , and  FIG. 8A , the actuator  321  and the rod assembly  322  described with reference to  FIGS. 7C, 7D, and 8B  or any other suitable actuator. The assembly  600 ′ may also include a lock block  210 ′ similar to the lock block  210  but with the engagement and actuation of the block  210  located on the same side. As illustrated the engagement portion  213  may be substantially the same as that of block  210 , and may include a shaped (cam) surface having substantially the same features as the peripheral wall  214  that defines and includes the groove  212 . In this example though, the rod  302  or  322  may be coupled to the engagement portion  213  to pivot the engagement portion toward and away from the fixed frame  110 . As such, the tilt-lock assembly  700  operates to lock out tilt (or engage the locking mechanism) upon pushing on the rod assembly  302  or  322 , which causes the downward rotation of the lock block toward the fixed frame, and unlocking (or disengagement) of the tilt-lock assembly occurs responsive to pulling on the rod assembly  302  or  322 , which rotates the lock block upward and away from the fixed frame. 
     In other embodiments, the tilt-disabling mechanism may be implemented using any suitable brake mechanism, such as a friction brake, that is operatively associated with at least one of the pivot shafts of the bike  10 .  FIG. 12  shows an example of a brake  700  operatively associated with one of the pivot shafts of the bike  10 , shown here as arranged to engage the front pivot shaft. The brake  700  may be configured to provide resistance, in some cases adjustably, to the rotation of one of the pivot shafts (e.g., front pivot shaft  132 ) and be actuatable to a position in which the brake  700  effectively prevents (or locks out) the rotation of the pivot shaft (e.g., front pivot shaft  132 ). In some embodiments, some forms of a tilt-disabling mechanism, such as brake  700 , may be provided at each of the pivot shafts (i.e. the front pivot shaft  132  and the rear pivot shaft  162 ). The brake  700  may use friction as the resistive force, or it may use a different form of resistance such as magnetic resistance. 
     One embodiment of the brake  700  is shown in the illustration in  FIG. 13 . The drum brake  800  shown in cross-section in  FIG. 13  may be used to implement the brake  700 . The drum brake  800  includes a drum  810  which is shown here as a substantially cylindrical member coaxially positioned with and fixed to the pivot shaft  801  (e.g., the front pivot shaft  132  or the rear pivot shaft  162  of the bike  10 ). As such, the drum  810  rotates or pivots in synchrony with the pivot shaft  801  as the bike pivots or tilts from side to side. The drum brake  800  includes a pair of shoes  812 - 1  and  812 - 2 , each shown here as an arcuate brake pad, which may be configured to engage substantially half of the circumference of the drum. Each of the shoes  812 - 1  and  812 - 2  is pivoted about a respective shoe pivot axis  811  such that the braking surface  813  of each shoe can be selectively positioned closer to or farther away from the interior (or braking) surface  815  of the drum  810 . The shoes may be actuated between the disengaged and engaged positions using a cam  816 . The cam  816  may be implemented using a non-circular (i.e. cammed) shaft or pin. In this example, the cam  816  is implemented using a pin having an oval or elliptical shape with one of its dimensions, minor diameter  817 , being smaller than the other dimension, major diameter  819 . In the disengaged position, the cam  816  is oriented with its narrow dimension in the arcuate (or circumferential) direction. As the cam  816  is rotated to orient its wider dimension in the arcuate (or circumferential)direction, the free ends of the shoes  812 - 1  and  812 - 2  are pushed outward toward the drum  810 , causing each of the shoes to contact the interior surface  815  of the drum  810  thereby applying frictional force to the drum  810  and thus to the pivot shaft  801 . The cam  816  may be actuated mechanically, such as via a lever  814 , which may be fixed to the cam  816 . Actuation of the shoes  812 - 1  and  812 - 2  may be achieved using any other type of local (e.g., mechanical) actuation device or remotely (e.g., via an electronic signal being transmitted to a solenoid or motor that drives the rotation of the cam  816 ). In other embodiments the mounting locations of the drum and the shoes may be reversed with the drum being mounted to the fixed frame and the shoes mounted to the moving frame. 
       FIG. 14  shows another example of a friction brake  900  which may be used to implement the brake  700 . The friction brake  900  includes a drum  910  fixed to the pivot shaft  901  (e.g., the front pivot shaft  132  or the rear pivot shaft  162  of bike  10 ) such that the drum  910  pivots in synchrony with the pivot shaft  901 . The brake  900  also includes a flexible or bendable friction pad  912 , shown here as a friction band or belt, which is wrapped, circumferentially, around the drum  910 . A first end  913  of the friction pad  912  is anchored to the fixed frame, e.g., at anchor  916 , which may be fixed to the fixed frame of the bike. The other end  915  of the friction pad is movable and operatively associated with an actuator (not shown) configured to move the end  915  toward and away from the first end  913 , as shown by arrow  919 , thereby decreasing or increasing the gap G between the two ends  913  and  915 , which results in increasing or decreasing, respectively, the friction force applied by the friction pad  912  on the drum  910 . In other embodiments, the mounting locations of the drum  910  and the friction pad  910  may be reversed, such as by mounting the drum  910  to the fixed frame and anchoring the friction pad  912  off the moving frame. 
       FIG. 15  shows yet another example of a brake  1000  operatively engaged to resist the rotation of a pivot shaft (e.g., front pivot shaft  132  or rear pivot shaft  162 ) of the bike. The brake  1000  is implemented as a disk brake operatively engaged with the pivot shaft  1001  (e.g., either one of the front or rear pivot shafts  132  or  162 , or an individual brake provided at each of the front or rear pivot shafts  132  and  162 ). The brake  1000  includes a disk  1010  fixed to the pivoting shaft  1001 , and a caliper  1012  assembly operatively positioned to apply friction to the disk  1010 . The caliper assembly  1012  may include a first caliper  1016 - 1  with a first friction pad  1018 - 1  fixed to the first caliper  1016 - 1 , and a second caliper  1016 - 2  provided with a second friction pad  1018 - 2 . An actuator, shown here as lever  1014 , is operatively associated with one of both of the calipers  1016 - 1  and  1016 - 2  to move one or both of the calipers toward and away from the disk  1010  to increase and decrease the frictional force on the disk  1010 . In this example, the lever  1014 , which is actuated by pivoting it about the pivot axis, as shown by arrow  1003 , is engaged, e.g., via a threaded stud  1015 , to the second friction pad  1018 - 2  to move the second friction pad  1018 - 2  toward and away from the disk  1010 , as indicated by arrow  1005 . In other embodiments, the mounting locations of the disk  1010  and the caliper assembly  1012  may be reversed, such as by operatively mounting the disk  1010  to the fixed frame and caliper assembly  1012  to the moving frame. 
     In some embodiments, at least one or both of the pivot shafts (e.g. front pivot shaft  132  and/or rear pivot shaft  162 ) or a portion thereof, may not be cylindrical. For example, a portion of the shaft (e.g. front pivot shaft  132  and/or rear pivot shaft  162 ) may have a different cross-sectional geometry (e.g., square as shown in  FIGS. 16A, 17A and 17B , or triangular, as shown in  FIG. 16B ). The pivot shaft, shown in cross-section and indicated as  166 A and  166 B in  FIGS. 16A and 16B , respectively, may be received in a housing  168 A and  168 B, which may also be non-circular. Whether circular or non-circular, the housing is large enough and/or suitably shaped to accommodate rotation of the non-cylindrical shaft  166 A or  166 B therein. When so received within the housing, one or more pockets or cavities  167  are defined between the shaft (e.g.,  166 A or  166 B) and the housing (e.g.,  168 A or  168 B, respectively) when the bike is in the nominal (non-tilted) position. For example, the shaft  166 A in  FIG. 16A  has a square transverse geometry and is rotatably received within a larger square housing  168 A defining four pockets  167  in each corner of the square housing  168 A when the bike is in the nominal (non-tilted) position. In the example in  FIG. 16B , the shaft  166 B has a triangular transverse geometry and is rotatably received within a larger triangular housing  168 A defining three pockets  167  in each corner of the square housing  168 A when the bike is in the nominal (non-tilted) position. In each case, the housing is sufficiently large to accommodate rotation of the smaller square or triangular shaft therein. While not shown, the square shaft  166 A or the triangular shaft  166 B may in other examples be rotatably received in a circular housing sufficiently large to accommodate the rotation of the non-circular shaft. The rotation of the shaft, and thus disabling of the tilting or pivoting movement of the bike may be achieved by the selective insertion of a blocking wedge  169  within one or more of the pockets  167 . The blocking wedge  169  may have substantially the same shape as that of the cavity  167  within which it is to be inserted. The blocking wedge  169  may be sized and shaped to substantially fill the cavity  167  within which it is to be inserted, such that when so inserted, the rotational degree of freedom of the shaft (e.g., shaft  166 A or  166 B) is effectively constrained. The blocking wedge  169  may be made for a substantially rigid material or a durable rubber material with sufficient hardness to substantially prevent the rotation of the non-circular shaft (e.g., shaft  166 A or  166 B) relative to the housing (e.g.,  168 A or  168 B, respectively). 
       FIGS. 17A and 17B  show an example of a tilt-disabling mechanism  570  operatively associated with a non-circular pivot shaft, shown here as a square pivot shaft  576 . The pivot shaft  576  is rotatably received within a housing  578 , which is sufficiently large and/or so shaped as to accommodate the pivoting of the pivot shaft  576 , shown in this example as also being square. The dimension of the square shaft  576  along the diagonal of the square is less than a dimension of the square housing  578  measured along the length of the square so as to accommodate rotation of the shaft  576  therein (as indicated by arrow  571 ). When the bike is in the nominal (un-tilted) position, the shaft  576  is oriented relative to the housing  578  such that the corners of the square shaft  576  point towards the wall of the square housing  578 , e.g., to a position midway between the corners of the square housing  578 , such as to define pockets  577  between the shaft  576  and the housing  578 . 
     The tilt-disabling mechanism  570  includes one or more locking members  579 , shown here as first and second pivoting levers  581 - 1  and  581 - 2 , respectively. Each locking member  579  (e.g., each of the levers  581 - 1  and  581 - 2 ) is movable between an engaged position in which a locking member  579  interferes with rotation of the pivot shaft  576  (as shown in  FIG. 17A ), and a disengaged position in which the locking member  579  does not interfere with rotation of the pivot shaft  576  (as shown in  FIG. 17B ). In the present example, each of the locking members is pivotally coupled to the fixed frame (e.g., to the housing  178 ) and includes a cam  583 , at least a portion of which is positioned in a respective pocket  577  when the locking member is pivoted to the engaged position. In some embodiments, the cam  583  may be located opposite an actuation end  585  of the pivoting lever, such as at near the pivot axis of the lever. In other embodiments, the locking members  579  may be differently implemented, such as by using one or more movable wedges, e.g., insertable into a respective pocket along the axial direction of the shaft  176 . 
     In other embodiments, the tilt-disabling mechanism (e.g., locking mechanism  200 ) may be implemented using a pin-and-hole locking mechanism. A protruding structure or pin may be coupled to one of the fixed frame and the moving frame, and a receiving feature or hole may be provided on the other one of the fixed frame or the moving frame. The pin and hole may be operatively associated with the respective frame to enable insertion of the pin into the hole, such that when so engaged, relative movement between the moving and fixed frames is substantially prevented. The pin and hole may be arranged such that insertion of the pin into the hole occurs in a direction that lies in a plane parallel to the fixed plane S, which includes the fixed plane itself. Thus, when so inserted into the hole, the pin may in effect create a rigid link between the moving frame and the fixed frame which lies in a plane parallel to the fixed plane S. 
     As shown, for example in  FIG. 18 , a protruding structure or simply protrusion  420 , shown here as a tapered pin, may be coupled to the moving frame  120 . An aperture or recess, which acts as the receiving feature or hole  430 , may be located on the fixed frame  110 . In some embodiments, the protrusion  420  may extend from the moving frame  120  in a direction toward the tilt axis A. The protrusion  420  and the receiving features  430  may be coupled to the moving frame  120  and the fixed frame  110 , respectively, in a manner that allows repositioning the protrusion  420  and/or the receiving feature  430  between an engaged position and a disengaged position. The engaged position is a position in which the protrusion  420  is engaged (i.e. is at least partially within) the receiving feature  430  and the disengaged position, as shown in  FIG. 18 , is a position in which the protrusion  420  is not engaged with (i.e. is not in) the receiving feature  430 . In some examples, the protrusion may be fixed to the moving frame  120  such that it tilts from side to side, as shown by arrow T, when the moving frame pivots or tilts about the axis A. In some such examples, the receiving feature  430  may be formed on or otherwise provided in a component (e.g., a rigid member) of the fixed frame  110 , and the component that includes the receiving feature  430  may be movably coupled to the fixed frame  110  such that it is selectively movable along direction E for repositioning it between the engaged and disengaged positions. In other examples, the receiving features  430  may remain fixed, while the protrusion  420  instead is movable (along direction E) to selectively move it between the engaged and disengaged positions. 
     Another example of a pin-and-hole locking mechanism is show in  FIG. 19A . In this example, a pin  2022  is coupled to the fixed frame  110 , with the length of the pin  2022  extending in a plane parallel to the fixed plane S. The pin  2022  is movably coupled to the frame  110  such that it can be selectively actuated in the direction  2021 , which is shown here as substantially parallel to the axis of the front pivot shaft  132 , and is thus also parallel to pivot axis A. The pin  2022  may be slidably coupled to a slot in the fixed frame (e.g., a slot in the upward extension  109 ). A receiving feature or hole is provided on the moving frame  120  to receive the pin  2022 . The hole is aligned to receive the pin when the bike  10  is in the neutral (untilted) position. For example, the pin  2022  and its cooperating hole may lie in the fixed plane S and mid-plane M, respectively and may thus align with one another to lock the bike  10  in the neutral position. In other examples, the pin and hole may lie in a different plane which may be parallel to the fixed plane S. Also, the pin  2022  need not be actuated along the direction of the pivot axis A. 
     Referring to the example in  FIG. 19B , the pin may be actuated in a direction angled (e.g., a perpendicular direction  2023 ) to the pivot axis A. The pin  2024  in this example is movably (e.g., slidably) coupled to the moving frame  120  and is configured for engagement with a hole provided on the fixed frame  110 . While the pin-and-hole locking mechanisms of these examples are shown as associated with the front pivot joint  130 , in other examples, similar pin-and-hole locking mechanisms may be provided elsewhere between the moving and fixed frames, such as proximate to the rear pivot joint of the bike  10 . 
       FIGS. 20A-D  show yet another example of a pin-and-hole locking mechanism. In this example, the receiving end (e.g., hole  830 ) of the locking mechanism is provided in block  831  attached to one of the pivot shafts, in this case the front pivot shaft  132 . As such, the hole  830  in this example is on the moving frame  120 . The hole  830  is shown here as a groove extending along the top side of the block  831 . However, in other embodiments, the hole  830  may be differently configured or positioned with respect to the moving frame. The insertable end (e.g., the pin  820 ) is provided on the fixed frame  110  and is configured to be actuated toward and away from the receiving end (e.g., the hole  830 ). The pin  820  is movable toward and away from the pivot shaft, and in this example, moving substantially perpendicularly to the pivot axis A. 
     The pin  820  is actuatable towards and away from the hole  830  by a linkage  840 . In the illustrated example in  FIGS. 20A-D , the linkage  840  includes an actuation link  842 , a fixed link  846 , and a connecting link  844  pivotally coupling the actuation link  842  to the fixed link  846 . The actuation link  842  has an actuation end  842 - 1 , which may be configured for manual actuation such as by including a handle  845  (e.g., a round or differently shaped knob). The opposite end  842 - 2  of the actuation link  842  is operatively coupled to the pin  820  via a slider link  848 . The slider link  848  is constrained to translate or slide in a direction toward the tilt axis A such as by being slidably received within a cylinder  849  that extends in a direction substantially perpendicular to the tilt axis A. The pin  820  is fixed to the free end of the slider link  848 . To operate the locking mechanism, the user applies a force on the actuation link  842 , e.g., in the direction shown by arrow  843 - 1 , which causes the slider link  848  to move away from the tilt axis A, out of cylinder  849  in the direction show by arrow  847 - 1 , thereby causing the pin  820  to move away from the hole  830  disengaging the locking mechanism. Conversely, to lock out the tilting or pivoting movement of the bike, the user actuates the actuation link  842  in the opposite direction, as shown by arrow  843 - 2 , which causes the link  842  to return to center, pushing the slider link  848  into the cylinder  849  and toward the tilt axis A (as shown by arrow  847 - 2 ), thereby causing the pin  820  to engage the hole  830 , when the bike is in the centered (un-tilted) position. The linkage  840  may be an over-center linkage in that it may be configured to be actuated in either direction, e.g., by pulling the handle  845  from the center position shown in  FIG. 20D  toward the bike (in the direction of arrow  843 - 1 ) or by pushing the handle  845  from the center position in  FIG. 20D  away from the bike (in the direction of arrow  843 - 2 ). The linkage may be bi-stable, e.g., on either side of the center position in  FIG. 20D , to maintain the locking mechanism in the disengaged position (of either  FIG. 20C  or in the opposite direction) until further actuated by the user. 
       FIGS. 21A  and B and  FIGS. 22A  and B show examples of tilt-disabling (or locking) mechanisms which use one or more pawls operatively positioned between the fixed and the moving frames. Such locking mechanisms may include a first engagement member and a second engagement member that are operable to interlock with one another. For example, one of the first and second engagement members may include at least one protrusion, and the other one of the first and second engagement members (e.g., one or more pawls) may define an engagement recess that receives the protrusion thereby interlocking the two engagement members. 
       FIGS. 21A  and B illustrate an example of a tilt-disabling or locking mechanism that can be used for locking out the tilting or leaning movement of the bike  10 . The locking mechanism  1700  includes a first engagement member  1720 , which may be provided on one of the fixed frame  110  or the moving frame  120 . The first engagement member  1720  includes a protrusion  1723 , which may extend in a direction that is generally parallel to the fixed plane S. The locking mechanism  1700  further includes a second engagement member  1712 , which may be provided on the other one of the fixed frame  110  or the moving frame  120 . As such, when the locking mechanism  1700  is disengaged, the first engagement member  1720  moves relative to the second engagement member  1712  whenever the moving frame  120  of the bike pivots or tilts about axis A. The second engagement member  1712  may include one or more rigid links, in this example including a pair of rigid links  1710 , referred to here as pawl links  1710 . Each of the pawl links  1710  has one end pivotally coupled, at pivot point  1711 , to the moving or fixed frame. The pivot points  1711  of the pawl links  1710  of the present example are located on opposite sides of the first engagement member  1720 . A step or ledge is defined along the length of each link  1710 . The two links  1710  may be operatively coupled to one another (e.g., via a sliding pin joint  1713 ) at the location of the ledges such that together, the two pawl links  1710  define an engagement recess  1734  sized to receive the protrusion  1723  of the first engagement member  1720 . The links  1710  may be actuated at the opposite end from the pivot point  1711 , referred to here as actuation end  1702 . As shown, when a force is applied to the actuation ends  1702  of the links, as indicated by arrow  1731 , which in some embodiments occurs in unison, the two link  1710  pivot, in opposite directions, about the pivot point  1711 , causing the engagement recess  1734  to lift away from the protrusion  1723 . Conversely, when the links  1710  are actuated toward the first engagement member  1702  and are thus pivoted in their respective opposite directions, the engagement recess  1734  is brought into engagement to receive the protrusion  1723 . A single actuator may be used to actuate the ends  1072  of both links, or more than one actuator (e.g., a pair of actuators) may be operatively engaged with a respective one of the actuation ends  1072  to move that actuation end  1702 , typically in unison with the other. In other embodiments, an actuator may actuate the two one or more links  1710  by applying a force at an intermediate position along the length of the link  1710 , such as near the recess  1734 . For example, in the case of two links  1710 , the two links may be actuated at once by applying a force at the pin joint  1713  (e.g., in the direction shown by arrow  1715 ). The one or more actuators may be coupled to the links  1710  compliantly, such as via a respective spring, which may provide certain advantages as described herein. In other examples, the actuation may be via one or more additional rigid links pivotally connected at the actuation ends  1702  of the pawl links. 
     Other arrangements of locking mechanisms including one or more pawls may be used in other examples.  FIGS. 22A and 22B  show embodiments using a single pawl link each of which is coupled to the fixed frame  110  and which cooperate with a protrusion  1723  on the moving frame  120  to lock out the tilting movement of the bike. The mounting locations of the pawl and protrusion may be reversed in other embodiments. In the embodiment in  FIG. 22A , the protrusion  1723  is provided at a free end of a bar  1717  which is fixed to one of the pivot shafts (e.g., front pivot shaft  132 ) of the bike  10 . Here, the bar  1717  extends radially from the pivot shaft  132  and thus in a direction substantially perpendicular to the pivot axis A. The bar  1717  is arranged such that its longitudinal direction is substantially aligned with the mid-plane of the moving frame (e.g., plane M). The pawl link  1710  defines the engagement recess  1734 , which is configured to receive the protrusion  1723  at least partially therein whereby engagement between the pawl link  1710  and the protrusion  1723  (by the positioning of the protrusion  1723  within the recess  1734 ) interferes with the rotation of the pivot shaft substantially locking the moving frame  120  in a position in which the mid-planes M and S of the moving and fixed frame, respectively, are substantially aligned. In the example in  FIG. 22B , the location of the protrusion  1723  and the recess  1734  are reversed, with the recess  1734  being provided by a trough defined between a pair of teeth on a toothed disk  1736  (e.g., a gear) and the protrusion  1723  being provided by the pawl end of the pawl link  1710 ′. In the example in  FIG. 22B , the toothed disk  1736  is rigidly mounted to the moving frame  120 , coaxially arranged and fixed to the forward end of the front pivot shaft  132  such that as the moving frame  120  tilts from side to side (i.e., pivots about axis A), the disk  1736  pivots about axis A in synchrony with the pivoting of the moving frame  120 , and more specifically in synchrony with the pivoting of the shaft  132  about axis A. Like the prior examples, the pawl link  1710 ′ is pivotally coupled at pivot point  1711  and actuatable away from the disk  1736  (as shown in  FIG. 22B , by arrow  1718 ) to disengage the tilt-locking mechanism, and toward the disk  1736  to engage the tilt-locking mechanism (as shown in phantom line in  FIG. 22B ). The disk  1736  may include a plurality of teeth as shown in  FIG. 22B , which may enable the moving frame to be lockable in a plurality of different positions, including the nominal (un-tilted) position, and one or more positions in which the moving frame is tilted relative to the fixed frame. In some embodiments, the disk  1736  may be provided with only a subset of the teeth shown in the example in  FIG. 22B , so as to define only a subset of possible tilt-disabled positions. In some embodiments, the disk  1736  may include only a pair of teeth (e.g., the adjacent teeth  1737 ) that define a recess  1734  for locking the bike only in the nominal (un-tilted) position. 
       FIGS. 24 and 25  show yet another example of a tilt-disabling or locking mechanism which is operatively associated with a pivot shaft (e.g., the front pivot shaft  132  or the rear pivot shaft  162 ) that pivotally couples the moving frame  120  to the fixed frame  110 . The tilt-disabling mechanism  170  in the example in  FIGS. 24 and 25  uses coaxially arranged interlocking shaft components to substantially lock-out the rotation of the shaft, in this case the front pivot shaft  132 , although in other examples, this type of locking mechanism may be associated with another pivot shaft (e.g., the rear pivot shaft) if one is used. The locking mechanism  170  may include a locking member  172  movably (e.g., slidably) received within the housing  134  that also houses the pivot shaft, in this case the front pivot shaft  132 . The locking member  172  is positioned coaxially with respect to the pivot shaft  132  and is configured to move longitudinally, along direction  171  which coincides with the axis of the shaft  132  and thus the tilt axis A, within the housing  134  between an engaged position and a disengaged position. In the engaged position, the locking member  172 , which is shown here as an annular ring with inner and outer shaped surfaces referred to as inner and outer interfaces  177  and  175 , respectively, is positioned to at least partially overlap a free end of the shaft  132 . 
     With continued reference to  FIGS. 24 and 25 , the pivot shaft  132  is fixed, at one end, to the moving frame  120 , has a free end which includes an engagement interface  176 , implemented here as a splined (e.g., toothed) outer surface. The inner interface  177  of the locking member  172  is shaped for a cooperating fit with the engagement interface  176  of the shaft  132 . In the present examples, the inner interface  177  of the locking member  172  is shaped essentially as a negative image to the engagement interface  176  such that when the locking member  172  is positioned over the shaped end of the pivot shaft  132  to overlap the shaped end, the engagement interface  176  and the inner interface  177  interlock (or mesh) with one another. This interlocking interferes with the rotation of the pivot shaft  132 . While the interlocking faces of the pivot shaft  132  and the locking member  172  are shown as splined (e.g., toothed) surfaces, the interface may be differently implemented in other examples, such as using a key and keyway, a differently shaped spline, one or more wedges as in the example in  FIGS. 16A  and B, meshed gears, angular contact faces, etc. The locking member  172 , when in the engaged position in which the its inner interface is interlocked with the engagement interface of the shaft, may be restrained from rotation about axis A by a similar engagement between its outer interface  175  and the inner surface of the housing  134 . For example, the outer surface of the locking member  172  and the inner surface of the housing  134  may be similarly shaped for a cooperating (in this case interlocking) engagement between correspondingly shaped angular contact faces. The interlocking may be achieved through meshing of gears, key-keyway interlocking, splined, tapered, or other angular contact surfaces that restrict relative rotational movement between the locking member  172  and the fixed housing  134 . 
     Other examples of interlocking shaft type locking mechanisms are shown in  FIGS. 26A and 26B , as well as  FIGS. 27A  through C. In the example in  FIGS. 26A and 26B , a pivot shaft of the bike (e.g., front pivot shaft  132 ) has an engagement interface  176 ′, shown here as a tapered spline surface. The engagement interface  176 ′ is defined by a portion of the outer surface of the pivot shaft  132  at a free end of the pivot shaft  132 . Unlike the example in  FIG. 24 , the shaped portion of the surface that provides the engagement interface  176 ′ tapers to the nominal shape of the shaft (e.g., cylindrical) along the length of the shaft (from the free end towards the pivotal joint that pivotally suspends the moving frame  120 ). The engagement interface  176 ′ cooperates with a locking member  172 ′. The locking member  172 ′, which may be a block  179 , is movable along the axial direction of the shaft (indicated by arrow  171 ) but is otherwise keyed to the housing  134 ′ so as to be non-rotatably received in the housing  134 ′. In the illustrated example, both the housing  134 ′ and the block  179  have a generally rectangular shape, which prevents rotation of the block  179  relative to the housing  134 ′. In other examples, the block  179  may be differently keyed to the housing  134 ′ so as to movably (e.g., slidably) but non-rotatably couple the locking member  172 ′ to the housing. The locking member  172 ′ (e.g., block  179 ) may be moved along the axial direction toward and away from the shaped end of the shaft  132  to respectively engage (see  FIG. 26B ) and disengage (see  FIG. 26A ) the tilt-locking mechanism  170 ′. To operate the locking mechanism  170 ′, the locking member  172 ′ (e.g., block  179  is moved (e.g., pushed) toward the shaft  132  to a position in which the shaped surface of the locking interface  177 ′ of the locking member  172 ′ with the engagement interface  176 ′, as shown in  FIG. 26B , thereby interfering with the rotation of the shaft  132 . To disengage the locking mechanism  170 ′, the locking member  172 ′ is moved in the opposite direction (e.g., pulled away from the shaft along the axial direction). Referring to  FIGS. 27A-C , the interlocking of the shafts may be achieved through interlocking of surfaces arranged at a different orientation with respect to the axial direction of the shaft. For example, a first engagement surface  176 ″ may be provided on a first locking member  172 ″, which in this example is mounted to the fixed frame  110 , and more specifically fixed to the housing  134 . The first locking member  172 ″ may be implemented as an annular ring which is arranged to position the first engagement surface  176 ″ transversely to the axial direction  171  of the shaft. A second engagement surface  177 ″ is operatively associated with the shaft  132 . The engagement surface  177 ″ is also oriented transversely to the axial direction  171  and is arranged to face the first engagement surface  176 ″. The second engagement surface  177 ″ is provided on a second locking member  186 , which is movably (e.g., slidably) but non-rotatably mounted to the shaft  132 . The second engagement surface  177 ″ may be keyed to the shaft  132  via key feature  188  to ensure that the second locking member  186  does not rotate relative to the shaft  132 . The second locking member  186  may be operatively associated with an actuator for moving the second locking member  186 , and thus the second engagement surface  177 ″, along the axial direction  171  between an engaged position (see  FIG. 27C ) and a disengaged position (see  FIGS. 27A and 27B ). The first and second engagement surfaces  176 ″ and  177 ″, respectively, have cooperating surface features that mesh or interlock with one another when the surfaces  176 ″ and  177 ″ are brought into contact with one another. The meshing or interlocking of the surfaces  176 ″ and  177 ″ of the locking mechanism  170 ″ substantially prevents any relative movement of the two surfaces and thus of the moving frame  120  relative to the fixed frame  110 . The locking mechanism  170 ″ may include an alignment or centering feature  191  that prevents engaging the locking mechanism  170 ″ unless the moving frame  120  (e.g., shaft  132 ) is in a predetermined position with respect to the fixed frame (e.g., housing  134 ), for example in the nominal (un-tilted) position. The centering feature  191  may be implemented using a protrusion (or male feature)  193  located on one of the two engagement surfaces, shown here on the first engagement surface  176 ″, and a recess (or female features)  195  configured to receive the protrusion  193  and located on the other one of the two engagement surfaces. The location of the male and female features may be reversed in other examples. In other embodiments, multiple alignment features may be provided at a plurality of radial positions along the two surfaces  176 ″ and  177 ″ to enable locking or engaging the tilt-lock mechanism  170 ″ in more than one position (e.g., in the un-tilted and at least one tilted position). 
       FIG. 28  illustrates another example of a bike  1010  which is selectively configurable as a tilt-enabled bike. The bike  1010  may include some or all of the components of bike  10  that enable the user to perform exercise simulating cycling. For example, the bike  1010  may include a seat assembly  60 , a handle bar assembly  40 , and a drive assembly  20 , all operatively coupled to a bike frame  1020 . The drive assembly  20  may include a crankshaft and a pair of pedals, each of which is coupled to an opposite side of the crankshaft, whereby the user rotates the crankshaft, in use, to perform exercise that simulates cycling. However, in this example, substantially the entire bike frame  1020  tilts (e.g., pivot about axis A′), e.g., in response to user force such as when the user is using the exercise bike  1010 . Here, instead of a base that supports a portion of the bike stationary with respect to a support surface, the bike includes a rocking base  1022  enabling substantially the full bike  1010  to pivot or lean. The base may include one or more transverse members (e.g., one or more beams oriented transversely to the frame such that they extend away from opposite sides of the mid-plane of the bike) with first and second lateral ends on opposite sides of the base. The opposite lateral ends of the base are thus disposed on and spaced apart from opposite sides of the frame. The lateral ends of the base are configured to move relative to the support surface during use of the bike thereby causing the frame to tilt or rock from side to side. For example, the lateral ends of the base may be spaced apart from the contact surface when the bike is supported on the contact surface by the base. The base may be operatively associated with a tilt-disabling mechanism that disables the movement of the first and second lateral ends relative to the support surface. 
     The rocking base  1022  may be implemented using one or more curved members  1024 . In some examples, the rocking base  1022  may include a first or front curved beam (not shown in this view) that supports a front portion of the upright bike frame, and a second or rear curved beam  1024 - 2 . Each of the curved beams may define an arc (or portion of the circumference of a circle), the radius of which may be selected to position the pivot axis A′ at a desired elevational location. In some embodiments, the front and rear curved beams may define arcs having slightly different radii so as to tailor the incline angle of the pivot axis A′ with respect to the ground. At least a portion of the one or more curved members  1024  (e.g., a mid-portion of curved member  1024 ′ in  FIG. 29A ) may contact the support surface (e.g., the ground  7 ) to support the bike onto the support surface. The one or more curved members  1024  may contact the support surface with the convex side of the curved member such that each of the opposite lateral ends of the curved member  1024  are spaced from the support surface. 
     The bike  1010  may be equipped with tilt-disabling mechanism  1040  operatively associated with the rocking base  1022  (e.g., with the one or more curved members  1024 ). The tilt-disabling mechanism  1040  may include at least one adjustable member (e.g., an adjustable or leveling foot, a spring member, or combinations thereof) configured to selective reduce or disable the movement of the opposite lateral ends of the base relative to the support surface. For example, the tilt-disabling mechanism  1040  may include a first leveling foot  1042 - 1  coupled to the curved member  1024  (e.g., rear curved beam  1024 - 2 ) on one side of the longitudinal mid-plane of the bike  1010  and a second leveling foot  1042 - 2  fixed to the curved member  1024  (e.g., rear curved beam  1024 - 2 ) on the opposite side of the longitudinal mid-plane of the bike  1010 . The leveling feet  1042 - 1  and  1042 - 2  may be spaced an equal distance from the longitudinal mid-plane of the bike  1010 . In some embodiments, that distance may be adjustable (e.g., by coupling the leveling feet  1042 - 1  and  1042 - 2  to the curved member  1024  such that they are movable along the length of the curved member  1024 ), which may facilitate adjusting (e.g., increasing or decreasing) the maximum tilt angle of the bike and thus a difficulty level of the exercise. 
     The leveling feet  1042 - 1  and  1042 - 2  may be adjustable to a first configuration or length, in which the rocking base is able to rock, and thereby lean the bike, substantially unimpeded. This configuration may be referred to as the tilt-enabled configuration, in which the tilt-disabling mechanism  1040  is substantially disengaged. In this configuration, the leveling feet may be substantially retracted above the elevational level of the bottom surface of the curved member  1024 . The leveling feet  1042 - 1  and  1042 - 2  may be adjustable to a second configuration or length, substantially equal to the distance between the ground  7  and the bottom surface of the curved member  1024  at the locations where the leveling feet  1042 - 1  and  1042 - 2  are attached to the curved member  1024 . As such, in this configuration, the left and right upwardly curved portions of the rocking base  1022  may be supported into a fixed position by the leveling feet, which constrains the rocking or tilting movement of the frame  1020 . In some embodiments, the leveling feet, alternatively or additionally to being length-adjustable, may be reversibly compressible (e.g., resilient or compliant). For example, each of the leveling feet may be implemented by or in combination with a resilient member, such as a spring (e.g., an elastomeric member or coil spring), which is able to reversibly and temporarily deform when the bike leans. In some such embodiments, the tilt lock-out may be achieved by increasing the stiffness of the spring to a level that would effectively render the spring substantially incompressible under normal user forces and/or by adjusting the location of the spring (e.g., by sliding the springs closer to the longitudinal mid-plane (e.g., to the center of the curved member  1024 . In some embodiments a combination of a spring and a retractable member may be used, such that the spring may act as a damper to the tilting or leaning of the bike, while the retractable rigid member may be used to fully disable or lock out the tilting movement of the bike. In various embodiments, a fixed height foot, a wedge, or a spring element may be movably associated with the rocking base  1022  and positionable between the elevated end of the rocking base and the ground to substantially fill the space between the elevated end of the rocking base and the ground thereby interfere with the movement of the rocking base. 
     In some embodiments, the rocking base may have an interface side (e.g., the side facing the ground) which has adjustable curvature (see  FIGS. 29A and 29B ). An elongate spring element  1030 , such as a strip or sheet spring may be attached to the underside of the rocking base  1022 ′ (e.g., to one or each of the curved members  1024 ′) and be selectively adjustable to vary the curvature of the spring element  1030  and thus of the underside of the rocking base  1022 ′. The spring element  1030  may be implemented using any suitable generally flattened arc-shaped piece of metal (e.g., a sheet or strip of spring steel), and may have a curvature substantially corresponding to the curvature of the rocking base  1022 ′ in its nominal or unloaded state, and a length substantially corresponding to the length of the curved member  1024 . The spring element  1030  may be fixed to one or each curved members  1024  of the rocking base  1022 ′ at least at one location along the lengths of the spring and curved member (e.g., about midway between the elevated ends of a curved member  1024 ). 
     An adjustment mechanism  1044  (e.g., a pop-pin, a rotating cam, or a threaded or sliding rod) may be operatively arranged to deflect each of the opposite ends  1031 - 1  and  1031 - 2  of the spring element  1030  away from the curved member  1024 ′ (in this illustration downward toward the ground  7 ) to vary the curvature of the spring element  1030 . For example, a first adjustment mechanism  1044 - 1 , for example a first threaded rod, is fixed to one end  1031 - 1  of the spring element  1030  and threadedly engaged with the curved member  1024 ′ to selectively push or pull the end  1031 - 1  of the spring element  1030  away from and toward the respective end of the curved member  1024 ′. Similarly, a second adjustment mechanism  1044 - 2 , for example a second threaded rod, is fixed to the other end  1031 - 2  of the spring element  1030  and threadedly engaged with the curved member  1024 ′ to push and pull the end  1031 - 2  of the spring element  1030  away from and toward the other end of the curved member  1024 ′. As the two ends  1031 - 1  and  1031 - 2  of the spring are deflected away from the curved member  1024 ′ the curvature of the spring  1030  is reduced. As the curvature of the spring element  1030  is reduced (i.e., the curved spring is flattened by operation of an adjustment mechanism), the amount by which the rocking base  1022  is able to tilt or rock from side to side is reduced, the spring element  1030  and one or more actuators (e.g., the adjustment mechanism  1044 - 1  and  1044 - 2 ) operate to disable the tilt- or lean-capability of the bike  1010 . 
     The spring element  1030  may be adjustable up to a state in which the spring is substantially flat and thus resting against the ground  7 , thereby substantially preventing any rocking motion of the base  1022 ′. In some examples, the adjustability of the underside curvature of the rocking base  1022  may be binary (e.g., between a curved and thus rocking state and a generally flat and thus rocking or tilt-disabled state). In other examples, the curvature of the underside of the rocking base may variably adjustable such as to enable adjustments to curvatures between the unloaded (nominal curvature) and flattened (minimum curvature) of the spring  1030 . In some such examples, the one or more adjustment mechanisms  1044  may be compliant (e.g., compressible) along the adjustment direction, indicated by arrow  1045 . The compliance of the one or more adjustment mechanisms  1044  may provide resistance to the tilting or leaning of the bike  1010  when the bike is in an intermediate tilt-enabled configuration (see, e.g.,  FIG. 29B ). A compliant adjustment mechanism  1044  may thus enable adjustments to the resistance to leaning as well as adjustments to and ultimately locking (or disabling) the leaning function of the bike  1010 . 
     With reference to  FIGS. 30A and 30B , a tilt-enabled or leaning bike according to another example may have a supporting base  1026  which allows the bike (e.g., bike  1010 ) to rock (or tilt or lean) from side to side, responsive to the compression of spring elements supporting the opposite lateral ends of the base, as shown in  FIGS. 30A and 30B . The base  1026  may be configured to support the bike (e.g., bike  1010 ) onto a support surface (e.g., ground  7 ) at a distance H above the support surface. For example, the base  1026  may include a first lateral support  1028 - 1  (e.g., first adjustable foot  1029 - 1 ) and a second lateral support  1028 - 2  (e.g., second adjustable foot  1029 - 2 ), each supporting an opposite side of the base  1026 , e.g., relative to the mid-plane of the bike. Each of the first and second lateral supports may be compressible or compliant such that as the user applies an out of plane force on the bike frame, a respective one of the compliant lateral supports  1028 - 1  or  1028 - 2  compresses, reducing the distance H associated with the unloaded state of the bike, thereby causing the base  1026  and thus the upward extending portions of the frame to lean to the side of the compressed lateral support. In some embodiments, compliant first and second lateral supports  1028 - 1  and  1028 - 2  may be implemented using respective first and second adjustable feet biasingly coupled to the respective lateral end of the base. In some embodiments, the resistance to tilting or leaning of the frame, which depends upon the compliance (e.g., spring force) of the compliant lateral supports  1028 - 1  or  1028 - 1  may be variable allowing the user to increase or decrease the tilting or leaning range of the bike and/or to ultimately disable the tilting or leaning function of the bike (e.g., by increasing the resistance to a level which in effect cannot be overcome by user force). Variable resistance to the tilting or leaning of the bike may be achieved, for example by increasing the preload on the respective spring that biasingly couples each of the first and second adjustable feet  1029 - 1  and  1029 - 2  to the base, such as by compressing by an initial amount before the user begins using the bike up to a level in which the springs are sufficiently preloaded or compressed to effectively eliminate any tilting or leaning of the bike under normal user forces. 
     An exercise bike system that allows the user to perform exercise simulation cycling is described. The exercise bike system may include a stationary bike (e.g., bike  10 ) which is capable of tilting from side to side, e.g., responsive to user forces, when the user is riding the stationary bike. In some embodiments, the exercise bike system includes a first bike frame that remains substantially stationary with respect to a support surface (e.g., fixed frame  110  of bike  10 ) and a second bike frame which is configured to support a user and which pivots relative to the first frame about a pivot axis in response to a force applied to the second frame by the user (e.g., moving frame  120  of bike  10 ). In some embodiments, the exercise bike system may include one or more electronic components, such as one or more sensors, a transceiver, one or more electronically controller actuators, or any combinations thereof. In some embodiments, the exercise bike system includes a display which is isolated from the pivoting movement of the bike. Movement of the display as the bike tilts (or leans) from side to side can be disorienting to the user. Thus, in some embodiments, a display of the exercise bike system, which is communicatively coupled to an electronic component on the bike, remains stationary while the second frame of the bike pivots relative to the first frame of the bike. 
     For example, referring to  FIG. 31A , the exercise bike system  800  may include a tilt-enabled bike (e.g., bike  10 ,  1010 ), and a display  180  configured to remain stationary when the moving frame of the bike is pivoting. The display  180  may be part of a display assembly  50 , which may be separate from the bike, as shown in  FIG. 31A , or connected to the bike, as shown in  FIG. 2 . In the embodiment in  FIG. 31A , the display  180  is mounted to a stand  52  that has a base, which similar to the base of the bike  10 , is configured to be supported on a support surface (e.g., ground  7 ). In this manner, when the moving frame  120  of the bike tilts from side to side, the display  180  remains stationary, just as the stationary or fixed frame  110 . 
     In other embodiments, the display  180  may be coupled to the fixed frame  110  of the bike  10  (see, e.g.,  FIG. 2 ). For example, the display  180  may be coupled, e.g., via display mast  182 , to the front stabilizer  112 - 1 , the front frame section  104 , or another component of the fixed frame  110 . As such, the display  180  may be configured to remain stationary while the moving frame  120  pivots about the pivot axis A. The display  180  may be pivotally mounted to its supporting structure (e.g., display mast  182  or stand  52 ) to enable the user to change the viewing angle of the display  180 . 
     In some embodiments, the display  180  may be pivotally mounted to the mast  182  using a swing arm  184 . The swing arm  184  may be a substantially rigid link, such as a curved tubular member, having a first end  183 - 1  pivotally connected to the mast  182  and a second end  183 - 2  supporting the display  180 . In some embodiments, the connection between the swing arm  184  and the display  180  may be rigid such that adjustments to the viewing angle may be obtained via pivoting of the swing arm  184  about the pivot interface  187 . In other embodiments, the display  180 , which may have a rigid mount provided on the rear side of the display housing  181 , may be pivotally coupled to the swing arm  184 , which may provide a second location for adjustments to the viewing angle of the display  180 . In some embodiments, a tray  185  may be provided near the display, shown here as coupled to the display assembly  50  at the location of the interface  187 . The tray  185  may be configured to hold various item(s) such as a smart phone, tablet, book, or other media, within reach while using the bike  10 . 
     In some embodiments, the pivot interface  187  may be configured as a sliding interface, which pivotally adjusts the viewing angle of the display  180  by moving the first end  183 - 1  of the swing arm  184  in the direction  189 . Such sliding interface may be implemented using one or more transverse pins at the upper end of the mast  182  and which are operatively engaged with a slot located at the end  183 - 1  and extending lengthwise along a portion of the swing arm  184 . By virtue of the curvature in the swing arm  184 , as the first end  183 - 1  of the swing arm  184  is pulled in a first direction toward the bike, the display  180  pivots in a first direction (clockwise in the view in  FIG. 2 ), and when the swing arm  184  is moved in the other direction away from the bike, the display  180  pivots in the opposite direction (counterclockwise in the view in  FIG. 2 ). In some such embodiments, in which the first end  183 - 1  of the swing arm  184  moves in relation to the display mast  182 , the tray  185  may be coupled to the swing arm  184 , specifically to the first end  183 - 1  such that is also moves (toward or away from the bike) as adjustments are made to the viewing angle of the display via the sliding pivot interface  187 . The pivot interface  187  may be implemented using any other suitable arrangement that effects a change in the angle of inclination of the display  180  with respect to a reference plane (e.g., the ground  7  or the base plane P passing through the front and rear stabilizers). 
     In some embodiments, the display  180  may be a touch display. The display  180  may be in communication (e.g., via a wired or wireless connection) with one or more electronic components on the bike, e.g., any one of at least one bike sensor, which may include but are not limited to a tilt sensor and one or more sensors arranged to measure cadence, heart rate, speed, temperature, power, or other performance metrics or biometrics. In some embodiments, at least one sensor may be a cadence sensor attached to the bike, which is operatively associated with the crankshaft, cranks, or crank wheel to measure their RPM and thus determine a cadence. In some embodiments, a sensor may be operatively associated with the resistance assembly to determine an amount of resistance applied, which may be used in combination with the RPM or cadence to determine power. Various types of sensors such as an infrared or other optical sensor, an accelerometer, a barometer, a gyroscope or gyrometer, a magnetometer, an EMF sensor, a potentiometer, a camera-based sensor, a fingerprint or other type of biometric sensor, or a force sensor may be used to record and/or compute exercise date (e.g., cadence or RPM, heart rate, power, calories, distance travelled, etc.) and other information about the operation of the bike (e.g., tilt angle, tilt-function status such as enabled or disabled, resistance level, etc.), which may be provided to the user, such as via the display  180 . 
       FIG. 31B  shows a block diagram of electronic components of the exercise bike system  800  according to some embodiments of the present disclosure. As shown in  FIG. 31B , a sensor  90  is attached to the bike  10 . The sensor  90  may be attached to any suitable component of the bike  10 , such as to the first bike frame (e.g., the fixed frame  110 ) or the second bike frame (e.g., the moving frame  120 ). The sensor  90  communicates (e.g., via a wired connection) with a transceiver  80  also attached to the bike  10 . Similar to the sensor  90 , the transceiver  80  may be attached to any suitable component of the bike  10 , such as to the first bike frame (e.g., the fixed frame) or the second bike frame (e.g., the moving frame). The transceiver  80  communicates with the display  180 . To communicate with the bike&#39;s transceiver, the display  180  may include a display transceiver  282 . The transceiver  80  on the bike  10  and the display transceiver  282  may be configured to wirelessly communicatively couple, e.g., via Wi-Fi, Bluetooth, ZigBee, radio frequency (RF), or any other suitable wireless communication protocol. The display transceiver  282  may be contained within a housing  181  of the display  180 . In some embodiments, the display  180  may be touch sensitive and may function as a console (e.g., for controlling one or more operations of the bike, such as for adjusting a bike setting, selecting an exercise program or media content to be displayed). In some embodiments, the display  180  may be integrated with a console that includes and I/O interface having one or more user controls (e.g., buttons, knobs, sliders, touch sensors some of which may be operatively associated with the display, etc.) for controlling operation(s) of the bike. 
     The display  180  may further include, in its housing  281 , a display processor  286 , which may be implemented using a central processing unit (CPU), graphics processing unit (GPU), digital signal processor (DSP), a microprocessor, a microcontroller, a single board computer, or any other suitable processing unit. The processor  286  is in communication with the display transceiver  282  and a display screen  284 . The processor  286  may receive signals from the display transceiver  282  and convert them into signals to be sent to the display screen  284  for displaying information on the display screen  284  related to the sensor  90 , such as information obtained from measurements by the sensor (e.g., heart rate, cadence, speed, resistance, tilt angle, etc.). In other embodiments, the display  180  may not have a processing unit, which may instead be located on the bike  10  or be part of an external electronic device  72 , such as the user&#39;s smart phone. In some such embodiments, the display  180  may receive signals (e.g., audio/video data and/or other information, such as sensor data) via the display transceiver  282  in a form ready for display by the display screen  284 . The display screen  284  may be implemented using any suitable display technology such as LED, LCD, OLED, QLED. In some embodiments, at least a portion of the display screen  284  may be touch sensitive, implemented using any suitable touch screen technologies such as resistive, capacitive, surface acoustical wave, infrared grid or other. 
     In some embodiments, the tilt-disabling mechanism may be electronically controlled, for example responsive to sensor signals and/or sensor measurements. In some embodiments, the tilt-disabling mechanism may be controlled (e.g., actuated) locally, for example by a mechanical actuator as the one described above with reference to  FIGS. 7A ,  7 B, and  8 , which may be directly connected to the locking mechanism. In other embodiments, actuation may occur by pushing a button on the bike, which may communicate (e.g., via a wired or wireless connection) with an electronic actuator  62  (see  FIG. 32 ), such as a solenoid, a servo or motor, or any other suitable electronic component, operatively associated with the locking mechanism to actuate the locking mechanism. In some embodiments, as shown in  FIG. 32 , the actuation may be initiated remotely such as via a wireless communication from an external electronic device (e.g., the user&#39;s smart phone  72 ), the console of the bike, which in some embodiments may be at least partially provided by a touch-enabled display  180 ), or other. In some such embodiments, as also shown in  FIG. 31B , the display  180  may send a control signal via the display transceiver  282  and responsive to user inputs to the transceiver  80  on the bike. The transceiver  80  may communicate the control signal to the actuator  62  for remotely actuating (e.g., engaging or disengaging) the tilt-disabling mechanism of the bike  10 . In some embodiments, the display  180  may be configured to communicate (e.g., wirelessly or via a wired connection) with an external electronic device  72 , such as a smartphone, a portable music or video player, a tablet, a portable computer, a Wi-Fi router or any other electronic device enabled for wireless communication, as shown, for example, in  FIG. 32 . 
     An exercise bike according to any embodiments of the present disclosure may include a console  850  for controlling one or more operations of the exercise bike. In some embodiments, the console  850  may be operable to display content and/or facilitate interaction with the user while the user is exercising. The console  850  may be supported by the frame (e.g., the fixed frame or the moving frame), or it may be supported on a stanchion separate from the bike frame. The support structure supporting the console  850  may position the console  850  in a convenient location, such as at a location whereby controls of the console are accessible to the user while exercising with the exercise bike and/or the display is visible to the user during use of the exercise bike. In some embodiments, at least a portion of the console  850 , such as the display  180 , may be removably mounted to its support structure (e.g., the bike frame or stanchion). In some embodiments, the console  850  and/or the console support structure may be configured to adjusting the vertical position, the horizontal position, and/or orientation of the console or a component thereof (e.g., the display) with respect to the rest of the frame (e.g., relative to the moving frame). 
       FIG. 35  illustrates a block diagram of a console  850 . As shown, the console  850  may include one or more processing elements (or simply processor)  852 , memory  854 , an optional network/communication interface  856 , a power source  858 , and one or more input/output (I/O) devices  860 . As discussed, the console  850  may also include a display  862 , which may implement display  180 , or which may be a separate, additional display. For example, the display  862  of the console  850  may be a touch-sensitive display that functions as an input/output device, while display  180  may be a passive display, which in some cases may have a larger screen size than that of display  862 , for providing content to the user while exercising. In other embodiments, both of the displays  180  and  862  may be either passive displays, or both may be touch sensitive. In yet other embodiments, the functionality of display  862  associated with console  850  may be provided by display  180 . The various components of console  850  may be in direct or indirect communication with one another, such as via one or more system buses or other electrical connections, which may be wired or wireless. 
     The processor(s)  852  may be implemented by any suitable combination of one or more electronic devices (e.g., one or more CPUs, GPUs, FPGAs, etc., or combinations thereof) capable of processing, receiving, and/or transmitting instructions. For example, the processor(s)  852  may be implemented by a microprocessor, microcomputer, graphics processing unit, or the like. The processor(s)  852  may include one or more processing elements or modules that may or may not be in communication with one another. For example, a first processing element may control a first set of components of the console  850  and a second processing element may control a second set of components of the console  850  where the first and second processing elements may or may not be in communication with each other. The processor(s)  852  may be configured to execute one or more instructions in parallel locally, and/or across a network, such as through cloud computing resources or other networked electronic devices. The processor  852  may control various elements of the exercise bike, including but not limited to the display (e.g., display(s)  862  and/or  180 ). 
     The display  862  provides an output mechanism for the console  850 , such as to display visual information (e.g., images, videos and other multi-media, graphical user interfaces, notifications, exercise performance data, exercise programs and instructions, and the like) to a user, and in certain instances may also act to receive user input (e.g., via a touch screen or the like), thus also functioning as an input device of the console. The display  862  may be an LCD screen, plasma screen, LED screen, an organic LED screen, or the like. In some examples, more than one display screens may be used. The display  862  may include or be otherwise associated with an audio playback device (e.g., a speaker or an audio output connector) for providing audio data associated with any visual information provided on the display  862 . In some embodiments, the audio data may instead be output via a Bluetooth or other suitable wireless connection. 
     The memory  854  stores electronic data that may be utilized by the console  850 , such as audio files, video files, document files, programming instructions, media, buffered data such as for executing programs and/or streaming content, and the like. The memory  854  may be, for example, non-volatile storage, a magnetic storage medium (e.g., a hard disk), optical storage medium, magneto-optical storage medium, read only memory, random access memory, erasable programmable memory, flash memory, or a combination of one or more types of memory components. In some embodiments, memory  854  may store one or more programs, modules and data structures, or a subset or superset thereof. The program and modules of the memory  854  may include firmware and/or software, such as, but are not limited to, an operating system, a network communication module, a system initialization module, and/or a media player. The operating system may include procedures for handling various basic system services and for performing hardware dependent tasks. Further, a system initialization module may initialize other modules and data structures stored in the memory  854  for the appropriate operation of the console. In some embodiments, the memory  854  may store, responsive to the processor  852 , exercise performance data (e.g., resistance level, bike tilt data, cadence, power, user heart rate, etc.) obtained or derived from measurements by one or more sensors on the exercise bike. The memory  854  may store one or more exercise programs and instructions, which cause the processor  852  to adapt one or more of the exercise programs based on the exercise performance data. The memory  854  may store the adapted exercise program(s) and may subsequently cause the processor  852  to control an operation of the exercise bike in accordance with the adapted exercise program(s). For example, the processor  852  may provide instructions the user, e.g., via the display or other component of the console, for adjusting the configuration of the bike (e.g., the resistance level, enabling or disabling tilt, etc.) or the user&#39;s performance (e.g., increasing or decreasing cadence) in accordance with the adapted exercise program. In some embodiments, the processor  852  may automatically, concurrently with or alternatively to providing instructions, adjust the configuration of the bike in accordance with the adapted exercise program. 
     The network/communication interface  856 , when provided, enables the console  850  to transmit and receive data, to other electronic devices directly and/or via a network. The network/communication interface  856  may include one or more wireless communication devices (e.g., Wi-Fi, Bluetooth or other wireless transmitters/receivers, also referred to as transceivers). In some embodiments, the network/communication interface may include a network communication module stored in the memory  854 , such as an application program interface (API) that interfaces and translates requests across the network between the network interface  856  and other devices on the network. The network communication module may be used for connecting the console  850 , via the network interface  856 , to other devices (such as personal computers, laptops, smartphones, and the like) in communication with one or more communication networks (wired or wireless), such as the Internet, other wide area networks, local area networks, metropolitan area networks, personal area networks, and so on. 
     The console  850  may also include and/or be operatively associated a power supply  858 . The power supply  858  provides power to the console  850 . The power supply  858  may include one or more rechargeable batteries, power management circuit(s) and/or other circuitry (e.g., AC/DC inverter, DC/DC converter, or the like) for connecting the console  850  to an external power source. Additionally, the power supply  858  may include one or more types of connectors or components that provide different types of power to the console  850 . In some embodiments, the power supply  858  may include a connector (such as a universal serial bus) that provides power to the an external device such as a smart phone, tablet or other user device. 
     The one or more input/output (I/O) devices  860  allow the console  850  to receive input and provide output (e.g., from and to the user). For example, the input/output devices  860  may include a capacitive touch screen (e.g., a touch screen associated with display  862 ), various buttons, knobs, dials, keyboard, stylus, or any other suitable user controls. In some embodiments, inputs may be provided to the console (e.g., to processor  852 ) also via one or more biometric sensors (e.g., a heart rate sensor, a fingerprint sensor), which may be suitably arranged on the exercise bike, such as by placing them at one or more locations likely to be touched by the user during exercise (e.g., on a handlebar of the bike). The input/output devices  860  may include an audio input (e.g., a microphone or a microphone jack). In some embodiments, the processor  858  may be configured to receive user inputs (e.g., a voice commend) via the audio input. One or more of the input/output devices  860  may be integrated with or otherwise co-located on the console. For example, certain buttons, knobs and/or dials, may be co-located with the display  862 , which may be a passive or touch sensitive display, and enclosed by a console housing. In some examples, one or more of the input devices (e.g., button for controlling volume or other functions of the console) may be located elsewhere on the exercise machine, e.g., separately from the display  862 . For example, one or more buttons may be located on the handlebar and/or a portion of the frame. One or more input devices (e.g., a button, knob, dial, etc.) may be configured for directly controlling a setting of the exercise bike such as the resistance (or braking) setting, damper level or an adjustable tilt damper, etc. In some embodiments, one or more of the input devices may indirectly control bike settings, such as via the processor. For example, an input device  860  may be in communication, directly or via the processor  852 , with a controller that actuates the resistance mechanism or other mechanism on the bike. 
     In some embodiments, one or more settings of the bike may be adjusted by the processing element  852  based on an exercise sequence or program stored in memory  854 . In some examples, the exercise program may define a sequence of time intervals at various resistance levels and/or with or without the tilting function of the bike engaged. In some embodiments, the console  850  may additionally or alternatively communicate the exercise sequence to the user, such as in the form of instructions (e.g. audio and/or visual) on the timing of and settings to which a user should adjust the configuration of the bike to correspond to the exercise program. In some embodiments the exercise program may be adapted (e.g., by processor  852 ) over time based on the user&#39;s prior performance of an exercise program or portion(s) thereof. The console  850  may be configured to enable the user to interact with the exercise program, such as to manually adjust it and/or override it (e.g., for exercising in manual mode). 
     In some embodiments, the console may be configured to present, independent of or concurrently with an exercise program, stored or streaming video content (e.g., scenery which may be recorded and/or computer generated), the playback of which may be dynamically adapted, in some embodiments, based on the user&#39;s driving of the moveable components of the exercise bike. For example, when the user&#39;s rotating the crank shaft faster the playback may speed up so as to give the impression of the user advancing through the scenery, and conversely, when the user&#39;s cadence decreases, the playback may slow down correspondingly to mimic the slower pace or cadence of the user. The scenery may be presented from the vantage point of the user or from a different vantage point, such as a vantage point behind or above (i.e., a bird&#39;s-eye view) an avatar of the user. In some embodiments, an exercise program and/or automatic control of the bike may be effected in synchrony with displayed video. For example, a video may display scenery that includes flat and hilled terrain, and the resistance level of the bike may be automatically adjusted, or instructed to be adjusted by the user, to mimic the user&#39;s perception that they are navigating similar terrain as that displayed in the video. The display may enable providing an interactive experience for the user, such as by providing an interactive environment according to any of the examples herein. In some embodiments, the interactive environment may be implemented in accordance with any of the examples described in U.S. Pat. No. 10,810,798, titled “Systems and Methods For Generating 360 Degree Mixed Reality Environments,” which is incorporated herein by reference for any purpose. 
     The foregoing description has broad application. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples. In other words, while illustrative embodiments of the disclosure have been described in detail herein, the inventive concepts may be otherwise variously embodied and employed, and the appended claims are intended to be construed to include such variations, except as limited by the prior art. 
     The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure. 
     All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority, but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.