Patent Publication Number: US-11649008-B2

Title: Multi-wheel transportation vehicles and related methods

Description:
RELATED APPLICATION 
     The presently disclosed subject matter claims the benefit of U.S. Provisional Patent Application Ser. No. 63/088,153, filed Oct. 6, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present subject matter relates to multi-wheeled vehicles, suspensions systems, and related methods. In particular, the present subject matter relates to three-wheeled vehicles that provide unique linkages between the wheels to provide a smoother ride to the user of the vehicle. 
     BACKGROUND 
     In recent years, interest in motor vehicles with innovative designs has grown in view of the continued expansion of urban areas, the large number of vehicles operating in these areas, and the problems associated therewith, including, for example, traffic jams, parking shortages, and environmental pollution. 
     In recent years, various attempts have therefore been made to develop a laterally tiltable multi-track vehicle, having either three or four wheels, in which the entire vehicle or a part thereof may tilt in toward a rotation center (e.g., a curve bend inner side) in a similar manner to a bicycle or motorcycle. In other words, both the body and wheels of a tiltable vehicle may lean into a curve during cornering such that the wheels stay parallel to the body throughout the curve. Accordingly, like a bicycle or motorcycle, such vehicles are statically in an instable equilibrium and would fall over without any external correction by the driver or another device. Unlike a bicycle or motorcycle, however, in which the vehicle can be easily stabilized by moving the center of gravity of the driver (i.e., via input from the driver), such tiltable vehicles generally require suspensions that can help stabilize the vehicle during cornering, or, for example, on banked roads. 
     Accordingly, various innovative suspensions have also been developed for laterally tiltable multi-track vehicles. Such suspensions, for example, generally incorporate a balancing device that can create a torque to influence the leaning angle of the vehicle. Additionally, for safety and ride comfort, such suspensions should also provide a spring/damping function between the body of the vehicle and the wheels of the vehicle, similar to the suspension spring/damper elements of a conventional motor vehicle. 
     While many have tried, a vehicle has not been developed that clearly provides rear wheel suspension that permits a more stable and comfortable ride and can provide easy adjustability as to the movement of the back wheels to adjust to both the road and how the vehicle responds to the road. 
     As such, a need exists for improving the suspension of a tiltable three-wheel transportation vehicle. 
     SUMMARY 
     The present subject matter relates to three-wheeled transportation vehicles and suspension systems as well as methods related thereto. In particular, the present subject matter provides three-wheeled vehicles with two rear wheels that permit the rear wheels to pivot without damaging the frame of the vehicle with the rear wheels being linked together such that the rear wheels move inversely to each other. 
     Thus, it is an object of the presently disclosed subject matter to provide three-wheeled transportation vehicles and suspension systems as well as methods related thereto. While one or more objects of the presently disclosed subject matter having been stated hereinabove, and which is achieved in whole or in part by the presently disclosed subject matter, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow proceeds. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present subject matter including the best mode thereof to one of ordinary skill in the art is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which: 
         FIG.  1    illustrates a perspective view of an embodiment of a transportation vehicle according to the present subject matter; 
         FIG.  2    illustrates a perspective view of the embodiment of the transportation vehicle according to  FIG.  1    with some components removed for clarity; 
         FIG.  3    illustrates a bottom side perspective view of a portion of the embodiment of the transportation vehicle according to  FIG.  1    showing an embodiment of a horizontal linkage according to the present subject matter; 
         FIG.  4    illustrates a bottom side perspective view of another portion of the embodiment of the transportation vehicle according to  FIG.  1    showing an embodiment of a horizontal linkage according to the present subject matter; 
         FIG.  5    illustrates a rear side perspective view of another portion of the embodiment of the transportation vehicle according to  FIG.  1   ; 
         FIG.  6    illustrates a top perspective view of the embodiment of the transportation vehicle according to  FIG.  1   ; 
         FIG.  7    illustrates a side plan view of the embodiment of the transportation vehicle according to  FIG.  1    showing embodiments of fairings secured to the vehicle according to the present subject matter; 
         FIG.  8    illustrates a top plan view of an embodiment of suspension locking system that can be used in conjunction with a transportation vehicle according to the present subject matter; 
         FIG.  9    illustrates a side perspective view of a portion of an embodiment of a transportation vehicle according to the present subject matter; 
         FIGS.  10 A and  10 B  illustrate a schematic side views of an embodiment of suspension locking system that can be used in conjunction with a transportation vehicle according to the present subject matter; 
         FIG.  11    illustrates a partial perspective view of the embodiment of suspension locking system according to  FIGS.  10 A and  10 B  that can be used in conjunction with a transportation vehicle according to the present subject matter; 
         FIG.  12    illustrates a rear perspective view of a portion of an embodiment of horizontal linkage that can be used in conjunction with a transportation vehicle according to the present subject matter; and 
         FIGS.  13 A- 13 C  illustrate schematic views of an embodiment of horizontal linkage in use on a transportation vehicle according to the present subject matter. 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent the seam or analogous features or elements of the present subject matter. 
     DETAILED DESCRIPTION 
     Reference now will be made to the embodiments of the present subject matter, one or more examples of which are set forth below. Each example is provided by way of an explanation of the present subject matter, not as a limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present subject matter without departing from the scope or spirit of the present subject matter. For instance, features illustrated or described as one embodiment can be used on another embodiment to yield still a further embodiment. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present subject matter, which broader aspects are embodied in exemplary constructions. 
     Although the terms first, second, right, left, front, back, top, bottom, etc. may be used herein to describe various features, elements, components, regions, layers and/or sections, these features, elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one feature, element, component, region, layer, or section from another feature, element, component, region, layer, or section. Thus, a first feature, element, component, region, layer, or section discussed below could be termed a second feature, element, component, region, layer, or section without departing from the teachings of the disclosure herein. 
     Similarly, when a feature or element is being described in the present disclosure as “on” or “over” another feature or element, it is to be understood that the features or elements can either be directly contacting each other or have another feature or element between them, unless expressly stated to the contrary. Thus, these terms are simply describing the relative position of the features or elements to each other and do not necessarily mean “on top of” since the relative position above or below depends upon the orientation of the device to the viewer. 
     Embodiments of the subject matter of the disclosure are described herein with reference to schematic illustrations of embodiments that may be idealized. As such, variations from the shapes and/or positions of features, elements, or components within the illustrations as a result of, for example but not limited to, user preferences, manufacturing techniques and/or tolerances are expected. Shapes, sizes and/or positions of features, elements or components illustrated in the figures may also be magnified, minimized, exaggerated, shifted, or simplified to facilitate explanation of the subject matter disclosed herein. Thus, the features, elements or components illustrated in the figures are schematic in nature and their shapes and/or positions are not intended to illustrate the precise configuration of the subject matter and are not necessarily intended to limit the scope of the subject matter disclosed herein unless it specifically stated otherwise herein. 
     It is to be understood that the ranges and limits mentioned herein include all ranges located within the prescribed limits (i.e., subranges). For instance, a range from about 100 to about 200 also includes ranges from 110 to 150, 170 to 190, 153 to 162, and 145.3 to 149.6. Further, a limit of up to about 7 also includes a limit of up to about 5, up to 3, and up to about 4.5, as well as ranges within the limit, such as from about 1 to about 5, and from about 3.2 to about 6.5. 
     According to one exemplary embodiment, the present disclosure comprises a multi-wheel transportation vehicle comprising one or more independent electric hub motors operatively mounted at respective wheels of the vehicle. 
     As disclosed herein, the present disclosure can comprise an improved motorized three wheeled vehicle. The exemplary method of achieving improved efficiency is to employ a three wheeled platform that permits vertical articulations in the rear wheels that correspond with each other permitting a shift in the center of gravity of the vehicle unlike conventional tricycles, which have limitations in that tricycles have the tendency to turn over when exposed to lateral acceleration, for example, when turning. The three-wheeled vehicle as disclosed herein acts to retain the side-to-side center of gravity along the central axis of the vehicle at all times. 
     The structure of the vehicle disclosed herein comprises one wheel at the front and two wheels at the rear. The two rear wheels articulate in an inverse manner, such that when one rear wheel articulates upward, the opposite rear wheel is constrained to articulate downward by the same amount, while both rear wheels remain parallel to each other in their vertical orientation and to the frame of the vehicle. The suspension arrangement of the rear wheels includes a series of mechanical linkages that transfer tire loading into the vehicle frame to permit the vehicle to achieve a vehicle attitude that allows the vehicle to tilt in turns. Each rear wheel is mounted on one end of a trailing wheel arm. The opposite end of each trailing arm is rotatably connected, or hinged, to one or more transverse arm shafts that can be transversely rigidly fixed to the frame of the vehicle. This arrangement enables the rear wheels to articulate rotatably about the one or more transverse arm shafts, while the rear wheels remain vertically parallel to the frame. 
     The rear wheel articulation is constrained to move opposedly, and to carry the vehicle weight by a horizontal transverse linkage. This horizontal linkage can comprise a bar, rod or beam that is pivotably connected, or hinged, at its center to the frame of the vehicle. The ends of the horizontal linkage can be linked to the intermediate area of the trailing wheel arms by tension links or suspension springs. Motive power for the vehicle can be provided by a battery powered electric hubmotor located on the axle of one or more of the vehicle wheels. 
     Referring to  FIGS.  1 - 6   , a transportation vehicle, generally designated  10 , is provided. The vehicle  10  can be a three wheeled transportation vehicle. The vehicle  10  can comprise a frame  12  having a front wheel  14  on an axle  16  within a fork  18  that can be steered by handlebars  20 . While shown in this embodiment with handlebars  20 , the vehicle  10  can utilize other steering systems, such as a steering wheel or single or dual control sticks. In some embodiments, the steering mechanism can swing, slide, or retract, for example, to facilitate operator access and egress. A seat  22  can be secured to the frame  12 . In some embodiments, the seat and frame configuration can provide a recumbent seat. The vehicle  10  can include a first rear wheel  24  and a second rear wheel  26 . The first rear wheel  24  can be mounted on an axle  24 A in a first trailing wheel arm  28  and the second rear wheel  26  can be mounted on an axle  26 A in a second trailing wheel arm  30  (see  FIG.  5   ). The first and second trailing wheel arms  28 ,  30  can be rotatably secured to a central suspension joint  32  such that each of the first and second trailing wheel arms  28 ,  30  can rotate about one or more shafts of the central suspension joint  32  in directions R to provide a general vertical displacement of the first and second rear wheels  24 ,  26 . The first and second trailing wheel arms  28 ,  30  are constrained to swing inversely to each other as will be explained further below. Wheel axle drop outs  24 B,  26 B can be used to secure and release the axles  24 A,  26 A and the respective rear wheels  24 ,  26  into and from the respective first and second trailing wheel arms  28 ,  30 . 
     The vehicle  10  can be an electric powered vehicle. For example, in some embodiments, the vehicle  10  can comprise one or more electric hub motors  34  that can be used to provide motive power. The electric hub motors  34  can be configured within the wheel hubs of one, two, or all three wheels. For example, in some embodiments as shown in  FIGS.  1  and  5   , the electric hub motors  34  can be within the rear wheels  24 ,  26 . Motive torque of the electric hub motors  34  can express itself through axle torque. The wheel axles  24 A,  26 A can be constrained from spinning, thereby converting the motor torque into traction at the tire tread. A torque arms  34 A as shown in  FIG.  4    can be rigidly attached to the axles  24 A,  26 A at one end and connected to the respective first or second trailing wheel arms  28 ,  30  at the opposite end to transmit the motor torque into the first and second trailing wheel arms  28 ,  30 . Alternatively, a clamping axle dropout (not shown) can be applied to rigidly constrain both ends of each axle from spinning. 
     To provide power to the electric hub motors  34 , one or more battery banks can be located within battery boxes  36  that can be rigidly attached to the frame  12  behind the front wheel  14 , for example. Footrests  35  can be provided on the vehicle  10 . In some embodiments, the footrests  35  can be rigidly but adjustably affixed to the top edges of the battery boxes  36  to allow for adjustment for varied rider height. In some embodiments, the footrests  35  instead can be rigidly but adjustably affixed to the frame  12 . 
     To control the power generated by the electric hubmotors  34 , a throttle  38  is provided that is in operable communication with one or more controllers  39  that is operably connected to the electric hub motors  34 . The one or more controllers  39  can thereby provide throttle controlled electric power to the hubmotors  34  as well as provide power for accessories. Using the battery powered electric hubmotors  34 , the throttle  38  and one or more controllers  39 , the user of the vehicle  10  can provide motive power to the vehicle  10  and control the speed of the vehicle  10 . 
     The connection of the first or second trailing wheel arms  28 ,  30  to the frame  12  and their controlled movement will now be described in more detail. As stated above, the first and second trailing wheel arms  28 ,  30  can be rotatably secured the central suspension joint  32  and can be constrained to swing inversely to each other. The vehicle  10  can comprise a horizontal linkage  40  that rotatably connects to the frame  12  and is linked to both the first and second trailing wheel arms  28 ,  30  on either side of the frame  12 . In some embodiments, the horizontal linkage  40  can be connected to the first and second trailing wheel arms  28 ,  30  at their intermediate lengths between their connections to the central suspension joint  32  and the respective rear wheels  24 ,  26 . The horizontal linkage  40  can link the first and second trailing wheel arms  28 ,  30  together such that the first and second trailing wheel arms  28 ,  30  move inversely to one another. For example, if the rear wheel  24  is pushed upward, the first trailing wheel arm  28  rotates upward about the shaft of the central suspension joint  32  and the horizontal linkage  40  is forced upward on the side that it is connected to first trailing wheel arm  28  while the horizontal linkage  40  is forced downward on the side that it is connected to second trailing wheel arm  30  as the horizontal linkage  40  is rotated around its connection to the frame  12  that acts as a fulcrum. The downward movement of the side of the horizontal linkage  40  connected to the second trailing wheel arm  30  brings the second trailing wheel arm  30  and the rear wheel  26  downward by an amount proportional to the upward movement of the rear wheel  24 . Thus, as first trailing wheel arm  28  articulates in a first direction, the horizontal linkage  40  is pivoted about the connection to the frame  12  causing the second trailing wheel arm  30  to articulate in a second opposing direction. 
     As shown in  FIGS.  1 - 6   , the horizontal linkage  40  can be pivotably connected to the frame  12  at a midsection  40 A while the horizontal linkage  40  can be linked to the first trailing wheel arm  28  between the first rear wheel  24  and the central suspension joint  32  proximal to a first end  40 B of the horizontal linkage  40  and the horizontal linkage  40  can be linked to the second trailing wheel arm  30  between the second wheel  26  and the central suspension joint  32  proximal to the second end  40 C of the horizontal linkage  40 . In some embodiments as shown in  FIGS.  3 - 5   , the horizontal linkage  40  can be secured to the frame  12  by a connection such as a shaft  42 A and cradle  42  such that horizontal linkage  40  is pivotable about the connection to the frame  12 . The shaft  42 A and cradle  42  firmly hold the horizontal linkage  40  to the frame  12  and act as a fulcrum to permit the horizontal linkage  40  to rotate about the shaft  42 . In the embodiment shown, the frame  12  can have a linkage indention  12 C that provides clearance space above the horizontal linkage  40  when secured by the shaft  42 A and cradle  42  to permit the back and forth pivoting about the shaft  42 A and cradle  42 . In some embodiments as shown, the horizontal linkage  40  can be secured to the frame  12  at a position in which the horizontal linkage  40  extends beneath the first and second trailing wheel arms  28 ,  30 . 
     In some embodiments as shown in  FIG.  12   , the horizontal linkage  40  can be secured to the frame  12  by a pintle  43  that extends outward from a rear end  12 D of the frame  12  such that the horizontal linkage  40  is pivotable about the connection to the frame  12 . Thereby, the pintle  43  can also act as a fulcrum to permit the horizontal linkage  40  to rotate about the pintle  43 . Having the horizontal linkage  40  pivotably secured to the pintle  43  at the rear end  12 D of the frame  12  provides more options for the operation of the horizontal linkage and related operational systems or subsystems. For example, being pivotably secured to such a pintle  43  can permit the attachment of a cam clamp suspension locking system, explained in more detail below, that includes a cam  102  and a lock disc  108  secured by fastener  112  to the horizontal linkage  40  as shown in dotted lines in  FIG.  12   . 
     As shown in  FIGS.  1 - 6   , the horizontal linkage  40  can be linked to the first trailing wheel arm  28  by a first tension link  44  and the horizontal linkage  40  can be linked to the second trailing wheel arm  30  by a second tension link  46 . In some embodiments, the first and second tension link  44 ,  46  can be loosely secured by fasteners  44 A,  46 A to the horizontal linkage  40 . For example, the horizontal linkage  40  can have recesses  48  on both ends  40 B,  40 C for receiving the respective first and second tension links  44 ,  46  with the fasteners  44 A,  46 A holding the respective first and second tension links  44 ,  46  in the recesses  48  of the horizontal linkage  40 . Additionally, first tension link  44  can be loosely secured to a shaft  28 B of the first trailing wheel arm  28  at an end receiver  44 B and the second tension link  46  can be loosely secured to a shaft  30 B of the first trailing wheel arm  30  at an end receiver  46 B. In this manner, the first and second tension links  44 ,  46  are provided with flexibility to move with horizontal linkage  40  and the respective first and second trailing wheel arms  28 ,  30  as the first and second trailing wheel arms  28 ,  30  rotationally articulate about the central suspension joint  32 . In an alternative embodiment, the horizontal linkage  40  can be linked to the first and second trailing wheel arms  28 ,  30  by springer-type suspension linkage at the rear end of both trailing arms as discussed in more detail further below in reference to  FIG.  9   . 
     Referring to  FIG.  9   , in some embodiments, the horizontal linkage  40  can be linked to the first and second trailing wheel arms  28 ,  30  by springer-type suspension linkage, such as a suspension spring. A suspension spring can compress under an instantaneous bump such as hitting a rock in a roadway without causing the horizontal linkage  40  to pivot which would lead to an inverse reciprocal movement of the other trailing wheel arm and wheel. In some embodiments, the suspension springs that provide the links between horizontal linkage  40  and the first and second trailing wheel arms  28 ,  30  can comprise mechanical suspension springs that use compress or tension springs therein. In some embodiments, the suspension springs that provide the links between horizontal linkage  40  and the first and second trailing wheel arms  28 ,  30  can comprise hydraulic suspension springs. In some embodiments, the suspension springs that provide the links between horizontal linkage  40  and the first and second trailing wheel arms  28 ,  30  can comprise pneumatic suspension springs. 
     As shown in  FIG.  9   , the vehicle  10  can comprise a pressurized air system  80 . The horizontal linkage  40  can be linked to the first trailing wheel arm  28  by a first air suspension spring  90 A and the horizontal linkage  40  can be linked to the second trailing wheel arm  30  by a second air suspension spring  90 B. The first and second air suspension springs  90 A,  90 B, which can be pneumatic cylinders, can be connected to the pressurized air system  80  to adjust the rigidity of the first and second air suspension springs  90 A,  90 B to modify the ability of the first and second air suspension springs  90 A,  90 B to absorb instantaneous bumps experienced by the respective first and second rear wheels  24 ,  26 . The pressurized air system  80  can comprise a compressor  82  which can compress air and feed it into an air tank  84 . A pressure switch  86  can be used to transport air from the air tank  84  to the lines  88 A,  88 B which provides the air to the connection on the respective first and second air suspension springs  90 A,  90 B closest to the horizontal linkage  40 . In the embodiment shown, at least a portion of the pressurized air system  80  is secured to a seat frame  15  of the frame  12  of the vehicle  10 . The link between the first and second air suspension springs  90 A,  90 B and the horizontal linkage  40  can be similar the links between the horizontal linkage  40  and the tension links described above. 
     The central suspension joint  32  provides a rotatable connection between the frame  12  and the first and second trailing wheel arms  28 ,  30  and helps distribute and lessen torque placed on the frame and a transverse arm shaft of the central suspension joint  32  generated by the articulation of the first and second trailing wheel arms  28 ,  30  about the central suspension joint  32 . To accomplish this task, the central suspension joint  32  can have a unique structure. In some embodiments as shown in  FIGS.  1 - 6   , the central suspension joint  32  can comprise a first central hub  50 A secured to the first side  12 A of the frame  12  and a second central hub  50 B secured to the second side  12 B of the frame  12 . Each of the first and second central hubs  50 A,  50 B can have a wide base body  52 A,  52 B with a flange  54 A,  54 B extending around the outer perimeter of the base body  52 A,  52 B. Each of first and second central hubs  50 A,  50 B can have an aperture  56 A,  56 B extending through a middle of each of the first and second central hubs  50 A,  50 B. The first and second central hubs  50 A,  50 B can be aligned on the frame  12  such that the apertures  56 A,  56 B and the flanges  54 A,  54 B of the first and second central hubs  50 A,  50 B are aligned. The central suspension joint  32  can also comprise a transverse arm shaft  58  securely extending through the frame  12  and the apertures  54 A,  54 B of the first and second hubs  50 A,  50 B along an axis HA as shown in  FIG.  6   . The transverse arm shaft  58  can have a first side  58 A extending out from the first central hub  50 A on which the first trailing wheel arm  28  can be rotatably secured and a second side  58 B extending out from the second central hub  50 B on which the second trailing wheel arm  30  is rotatably secured. In particular, in some embodiments, the first trailing wheel arm  28  can have a sleeve  28 A that is configured to slide on to and pivot about the first side  58 A of the transverse arm shaft  58  and the second trailing wheel arm  30  can have a sleeve  30 A that is configured to slide on to and pivot about the second side  58 B of the transverse arm shaft  58 . The first and second central hubs  50 A,  50 B can extend up to about the sleeves  28 A,  30 A of the respective sides of the transverse arm shaft  58 . A fastener such as an end cap or a cotter pin can be used to prevent the unwanted or unintentional removal of the sleeves  28 A,  30 A from the transverse arm shaft  58 . 
     The first and second hubs  50 A,  50 B can be secured to the respective sides  12 A,  12 B of the frame  12  at the flanges  54 A,  54 B. For example, a plurality of fasteners  55  can be used to secure the first and second hubs  50 A,  50 B to the respective sides  12 A,  12 B of the frame  12  at the flanges  54 A,  54 B. In some embodiments, the size and the number of fasteners  55  can vary and can be dependent upon the expected torque. For example, in some embodiments, the number of fasteners  55  can range between about 4 and about 30. in some embodiments, the number of fasteners  55  can be between about 6 and about 24. Without being held to any particular theory, it is believed that having a plurality of fasteners can facilitate the distribution of the torque placed on the frame  12  generated by the articulation of the first and second trailing wheel arms  28 ,  30 . 
     Additionally, the base body  52 A of the first central hub  50 A and the base body  52 B of the second central hub  50 B can have diameters as measured at the flanges  54 A,  54 B that engage the frame  12  and hold the first and second central hubs  50 A,  50 B to the frame  12  that distribute and lessen the torque placed on the frame  12  and transverse arm shaft  58  by the articulation of the first and second trailing wheel arms  28 ,  30  about the transverse arm shaft  58 . In some embodiments, the base bodies  52 A,  52 B of the first and second central hub  50 A,  50 B can have diameters as measured at the flanges  54 A,  54 B that are at least about three times a diameter of the transverse arm shaft  58 . In some embodiments, the base bodies  52 A,  52 B of the first and second central hub  50 A,  50 B can have diameters as measured at the flanges  54 A,  54 B that are at least about five times a diameter of the transverse arm shaft  58 . In some embodiments, the base bodies  52 A,  52 B of the first and second central hub  50 A,  50 B can have diameters as measured at the flanges  54 A,  54 B that are at least about ten times a diameter of the transverse arm shaft  58 . In some embodiments, the base bodies  52 A,  52 B of the first and second central hub  50 A,  50 B can have diameters as measured at the flanges MA,  54 B that are about nine times a diameter of the transverse arm shaft  58 . 
     In some embodiments, the central suspension joint can comprise a first central hub securable to the first side of the frame and a second central hub securable to the second side of the frame. The first central hub can comprise a base body with a flange extending around the outer perimeter of the base body and a first transverse arm shaft extending outward from a central portion of the first central hub. The second central hub can comprise a base body with a flange extending around the outer perimeter of the base body and a second transverse arm shaft extending outward from a central portion of the second central hub. The first and second central hubs can be positioned on the frame such that the flanges of the first and second central hubs are aligned to permit fasteners to fasten both the first and second central hubs together on the frame. Additionally, the first and second transverse arm shafts are aligned with each other along an axis. In such embodiments, the first trailing wheel arm can be rotatably secured to the first transverse arm shaft and the second trailing wheel arm can be rotatably secured to the second transverse arm shaft. As above, the base body of the first central hub and the base body of the second central hub can have diameters as measured at the flanges that engage the frame and hold the first and second central hubs to the frame to distribute and lessen a torque placed on the frame generated by the articulation of the first and second trailing wheel arms about the transverse arm shaft. 
     Referring to  FIG.  7   , to increase the usability of the vehicle  10 , the frame  12  can be encased in a covering  70  to protect the user from the sun and inclement weather. For example, the vehicle  10  can comprise fairings  72 ,  74 ,  76  that may be optionally affixed to the frame  12 . For instance, a nose cone  72  can be secured to the front fork  18  and a passenger fuselage, or upper frame fairing,  74  can be secured to the frame  12 . The upper frame fairing  74  may move relative to the frame  12  via hinges or slides to facilitate operator access. Additionally, nacelle fairings  76  may be optionally affixed to the first and second trailing wheel arms  28 ,  30 . 
     The vehicle  10  can operate with two distinct suspension modes. The unconstrained operational mode allows the vehicle to bank around corners, steered and trimmed mechanically by the physical and balancing inputs from the rider. The constrained operational mode forces the horizontal linkage  40  into a more rigid stance/posture such that the vehicle  10  behaves more like a traditional tricycle. The horizontal linkage  40  can be connected at its midpoint to the frame  12  as described above via a cradle joint  42  or a pintle that allows relative rotation about a fore-and-aft axis. To place the vehicle  10  in the constrained operational mode, the vehicle  10  can comprise a suspension lock system. For example, in the embodiment shown in  FIGS.  1 - 6  and  8   , the vehicle  10  can comprise a cable harness system  60  that applies tension on either side of the horizontal linkage  60  to constrain the relative rotation of the horizontal linkage  40  to the frame  12 . The cable harness system  60  can comprise an actuator  62 , a cable harness  64  and a cable binder  66 . The tensioning of the cable harness system  60  can be affected by the actuator  62 , which can be an electromechanical actuator, that applies tension to the cable harness  64 . The direction of the tension in the elements of the Cable Harness is redirected by the use of cable sheaves  68  within the sheave block  65  which is fixedly attached to the frame  12 . 
     Referring to  FIG.  8   , the cable harness system  60  can be used to constrain the tiling of the vehicle  10  when the vehicle  10  is travelling under a certain speed. In this manner, the cable harness system  60  can be used to force the vehicle upright and to behave as a tricycle. For example, when vehicle speed decreases to speed less than about 8 miles per hour, an electrical signal can be relayed from the hubmotor controller  39  to force the electromechanical actuator  62  to extend the cable harness  64 . The actuator  62  can tension cable harness  64 . A cable binder  66  can rigidly connect two sections of the cable harness  64  such that a loop is formed at the center of the cable harness  64 . The electromechanical actuator  62  is rigidly mounted to frame  12  and controlled by an electrical signal relayed from the hubmotor controller  39 . At speeds below a certain level, an actuator piston of the actuator  62  extends to apply tension to the center loop of the cable harness  64 . Through the clamping action of the cable binder  66 , both ends of the cable harness  64  can be in tension from the same direction. Each end of the Cable Harness passes through the sheave block  65 , redirecting cable tension such that tension is applied between the horizontal linkage  40  and the rear dorsal area of the frame  12 . The ends of the cable harness  64  can be affixed to the horizontal linkage  40  such that tension on the cable harness  64  constrains the relative rotation of horizontal linkage  40  to the frame  12 . The cable binder  66  can work with the sheave block  65  to get the cable harness  64  to pull in the manner and direction desired. 
     In other embodiments, the vehicle  10  can comprise different suspension lock systems. For example, in some embodiments as shown in  FIGS.  10 A- 11   , the vehicle  10  can comprise a suspension lock system such as a cam clamp locking system  100 . The cam clamp locking system  100  can comprise a rotatable cam  102  that can be connect to an actuating lever  104 . The actuating lever  104  can be secured to the frame  12  such that the lever  104  is accessible between the legs of the user of the vehicle when the user is driving the vehicle  10 . The lever  104  can rotate an actuator  105  which in turn rotates the cam  102  between a locked position and unlocked position. The cam clamp locking system  100  can comprise an opposing gusset  106  with a space between the cam  102  and the gusset  106 . The cam clamp locking system  100  can also comprise a lock disc  108  secured to the horizontal linkage  40  by fasteners  112  shown in  FIG.  11   . Thereby, the lock disc  108 , which can be in the shape of a full disc or a half disc, moves or pivots as the horizontal linkage  40  moves or pivots. The lock disc  108  can be positioned in the space between the cam  102  and the gusset  106 . In operation, as lever  104  is pulled upward by the user, the actuator  105  rotates the cam  102 . As the cam  102  is rotated, the cam  102  presses the lock disc  108  against the gusset  106  holding the lock disc  108  and horizontal linkage  40  in a stationary position for operating the vehicle  10  in the constrained operational mode. To revert to the unconstrained operational mode, the lever  104  can be lowered rotating the cam  102  back to its unlocked position and releasing the lock disc  108 . 
     In this manner, the cam clamp locking system  100  provides a simple and effect way to lock the suspension of the rear wheels in a specific position in the constrained operational mode by simply pulling the lever  104  upward. The cam clamp locking system  100  can be activated when the horizontal linkage  40  is in an equilibrium state as show in  FIG.  13 A  to place the vehicle  10  in the constrained operational mode. Additionally, the cam clamp locking system  100  can be activated when the horizontal linkage  40  is in a tilted state as show in  FIG.  13 B or  13 C  to place the vehicle  10  in the constrained operational mode while in the tilted state. Just as easily, the cam clamp locking system  100  can be deactivated to place the vehicle  10  in the unconstrained operational mode so that the horizontal linkage  40  and the vehicle  10  can freely shift between the equilibrium and tilted states. 
     As Shown  FIGS.  13 A- 13 C , in the unconstrained operational mode, the vehicle can operate to some varying degree between the equilibrium and two tilted states. As the rear wheel  24  is forced to rotate upward in a direction K 1  as shown in  FIG.  13 B , the first end of the horizontal linkage  40  that is secured to an underside of the first trailing wheel arm is pulled upward causing the horizontal linkage  40  to pivot or rotate about the pintle  43  in a direction P 1 . This, in turn, causing the second end of the horizontal linkage  40  that is secured to an underside of the second trailing wheel arm to be pulled downward such that the rear wheel  26  moves downward in the direction K 2  in an inversely proportional manner to the rear wheel  24 . Similarly, as the rear wheel  26  is forced to rotate upward in a direction K 3  as shown in  FIG.  13 C , the second end of the horizontal linkage  40  that is secured to an underside of the second trailing wheel arm is pulled upward causing the horizontal linkage  40  to pivot or rotate about the pintle  43  in a direction P 2 . This, in turn, causing the first end of the horizontal linkage  40  that is secured to an underside of the first trailing wheel arm to be pulled downward such that the rear wheel  24  moves downward in the direction K 4  in an inversely proportional manner to the rear wheel  26 . 
     For the purposes of describing and defining the present invention it is noted that the use of relative terms, such as “substantially”, “generally”, “approximately”, and the like, are utilized herein to represent an inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. 
     These and other modifications and variations to the present subject matter may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present subject matter, which is more particularly set forth herein above and any appending claims. In addition, it should be understood the aspects of the various embodiments may be interchanged either in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the present subject matter.