Abstract:
A simplified method is provided for controlling a motor of a bicycle component, especially a power assisting apparatus for a derailleur or a suspension. The method of controlling a motor of a bicycle assembly, basically comprising the steps of supplying current to the motor to move a bicycle component between a first position and a second position, and monitoring current flow to the motor during movement of the bicycle component. Then, stopping flow of current to the motor upon detection of an overcurrent to the motor due to the bicycle component reaching one of the first and second positions after being driven from the other of the first and second positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/274,235, filed Mar. 9, 2001. The entire disclosure of U.S. Provisional Patent Application Serial No. 60/274,235 is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention generally relates to a bicycle transmission. More specifically, the present invention relates controlling a motor of a bicycle component used in a bicycle transmission. 
     2. Background Information 
     Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One part of the bicycle that has been extensively redesigned is the transmission or drive train of the bicycle. Specifically, manufacturers of bicycle components have been continually improving shifting performance of the various shifting components such as the shifter, the shift cable, the derailleur, the chain and the sprocket. 
     Recently, bicycles have been provided with an electronic drive train for smoother shifting. These electronic drive trains include a rear multi-stage sprocket assembly with a motorized rear derailleur and a front multi-stage sprocket assembly with a motorized front derailleur. These derailleurs are electronically operated by a cycle computer for automatically and/or manually shifting of the derailleurs. 
     A typical bicycle transmission is operated by a shift operating wire connected between the transmission and a manually operated shift operating device mounted on the handlebar. The rider operates the shift operating device to selectively pull or release the shift operating wire which, in turn, operates the transmission in the desired manner. 
     One of the goals of bicycle transmission design is to make the transmission easy to operate with a minimum amount of effort. This involves minimizing the force needed to operate the shift operating device as well as minimizing the amount of unnecessary movement of the shift operating device. In the case of bicycle transmissions such as derailleurs which are used to shift a chain from one sprocket and move it to another can be quite large, especially when the destination sprocket is substantially larger than the originating sprocket and the rider is exerting substantial pedaling force on the chain. The necessary operating force can be reduced by operating the shift operating device when only a small pedaling force is being applied to the chain, but that requires the rider to consciously alter his or her pedaling technique and/or consciously operate the shift operating device only when a small pedaling force is being applied to the chain. That can be very distracting, especially in a racing environment. Also, the actuation of ratio of some derailleurs may be somewhat large. Consequently, the shift operating wire must move a substantial distance to fully move the chain from one sprocket to another, thus requiring the rider to move the shift operating device by a correspondingly large amount. 
     In view of the above, there exists a need for a bicycle transmission which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a simplified method of controlling a motor of a bicycle component. 
     Another object of the present invention is to provide a power assist for a front derailleur. 
     The foregoing objects can basically be attained by providing a method of controlling a motor of a bicycle assembly, comprising the steps of supplying current to the motor to move a bicycle component between a first position and a second position; monitoring current flow to the motor during movement of the bicycle component; and stopping flow of current to the motor upon detection of an overcurrent to the motor due to the bicycle component reaches one of the first and second positions after being driven from the other of the first and second positions. 
     The foregoing objects can also be attained by providing a bicycle assembly, comprising a motor having an overcurrent detecting circuit operatively coupled to a power input line of the motor to interrupt current flow to the motor upon detection of an overcurrent; and a bicycle component operatively coupled to the motor to move the bicycle component between a first position and a second position such that the overcurrent occurs in the motor when the bicycle component reaches one of the first and second positions after being driven from the other of the first and second positions. 
     These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the attached drawings which form a part of this original disclosure: 
     FIG. 1 is a side elevational view of a conventional bicycle with an electronically controlled drive train in accordance with a first embodiment of the present invention; 
     FIG. 2 is a top plan view of the handlebar portion of the bicycle illustrated in FIG. 1 with a shift control unit and a pair of shifting devices coupled thereto; 
     FIG. 3 is a perspective view of the front derailleur assembly that incorporates a shift assisting apparatus according to the present invention for shifting a bicycle transmission or drive train; 
     FIG. 4 is a partially perspective view the shift assisting apparatus for the front derailleur assembly illustrated in FIG. 3 with the derailleur and crank arm removed; 
     FIG. 5 is a perspective view of the motorized actuator of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4; 
     FIG. 6 is a flowchart illustrating a motor control routine for stopping the motor of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4; 
     FIG. 7 is a graph illustrating the current flow to the motor verses movement of the front derailleur during a shift operation of the front derailleur assembly illustrated in FIGS. 3 and 4; 
     FIG. 8 is a schematic diagram illustrating the operation of the motor of the front derailleur assembly; 
     FIG. 9 is a schematic diagram illustrating the overcurrent detecting circuit for stopping the operation of the motor of the front derailleur assembly; 
     FIG. 10 is a bottom plan view of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4 with portions broken away for purposes of illustration; 
     FIG. 11 is a cross sectional view of the motorized actuator of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4, with the driving axle in a first position; 
     FIG. 12 is a cross sectional view of the motorized actuator of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4, with the driving axle in a second position; 
     FIG. 13 is a cross sectional view of the motorized actuator of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4, with the driving axle in a third position; 
     FIG. 14 is a perspective view of a portion of the driving axle of the motorized actuator of the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4; 
     FIG. 15A is a side view of the mounting member used with the shift assisting apparatus for the front derailleur assembly illustrated in FIGS. 3 and 4, and illustrating the configuration of control surfaces; 
     FIG. 15B is a cross sectional view of the mounting member illustrated in FIG. 15A taken along line  15 B— 15 B in FIG. 15A; 
     FIG. 16 is a side elevational view of the shift assisting apparatus illustrated in FIGS. 3 and 4 in an idle state; 
     FIG. 17 is a side elevational view of the shift assisting apparatus illustrated in FIGS. 3 and 4 when the driving axle is rotated in a first direction; 
     FIG. 18 is a side elevational view of the shift assisting apparatus illustrated in FIGS. 3 and 4 showing the derailleur positioning cam rotating with the rotating member for pulling the derailleur actuating wire; 
     FIG. 19 is a side elevational view of the shift assisting apparatus illustrated in FIGS. 3 and 4 when the shift assisting apparatus has completed the shifting operations; 
     FIG. 20 is a side elevational view of the shift assisting apparatus illustrated in FIGS. 3 and 4 when the driving axle is rotated in a second direction; 
     FIG. 21 is a side elevational view of the shift assisting apparatus illustrated in FIGS. 3 and 4 when the shift assisting apparatus has completed the shifting operations; 
     FIG. 22 is a partial side elevational view of a conventional bicycle with an electronically controlled front suspension in accordance with a second embodiment of the present invention; 
     FIG. 23 is a longitudinal cross-sectional view of one of the front cylinders for the front suspension assembly in accordance with the present invention; 
     FIG. 24 is a schematic diagram illustrating the operation of the motor of the front suspension assembly; 
     FIG. 25 is a schematic diagram illustrating the overcurrent detecting circuit for stopping the operation of the motor of the front suspension assembly; 
     FIG. 26 is a flow chart illustrating a motor control routine for stopping the motor of either the shift assisting apparatus for the front derailleur assembly or the motor for the front suspension assembly; 
     FIG. 27 is a graph illustrating the current flow to the motor versus time period of energization of the motor of either the front derailleur assembly or the front suspension assembly, when the overcurrent is used to stop the device; and 
     FIG. 28 is a graph illustrating the current flow to the motor versus time period of energization of the motor of either the front derailleur assembly or the front suspension assembly when the motor is stop after a predetermined period but before an overcurrent occurs. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to FIGS. 1-3, a bicycle  10  is illustrated with an electronically controlled drive train  12  in accordance with a first embodiment of the present invention, as discussed below. The bicycle  10  basically has a frame  14  and a pair of wheels  15 , with the rear wheel being driven by the drive train  12 . The bicycle  10  and its various components are well known in the prior art, except for the improved portions of the drive train  12  of the present invention. Thus, the bicycle  10  and its various components will not be discussed or illustrated in detail herein, except for the components that relate to the drive train  12  of the present invention. Moreover, various conventional bicycle parts such as brakes, additional sprockets, etc., which are not illustrated and/or discussed in detail herein, can be used in conjunction with the present invention. 
     As used herein, the terms “forward, rearward, upward, above, downward, below and transverse” refer to those directions of a bicycle in its normal riding position. Accordingly, these terms, as utilized to describe the present invention in the claims, should be interpreted relative to bicycle  10  in its normal riding position. 
     Still referring to FIGS. 1-3, the drive train  12  basically includes a rear multi-stage sprocket assembly  16  with a motorized rear derailleur assembly or chain shifting device  18 , a front multi-stage sprocket assembly  20  with a motorized front derailleur assembly or chain shifting device  22 , a chain  24  extending between the rear multi-stage sprocket assembly  16  and the front multi-stage sprocket assembly  20 , and a pair of pedals  26  mounted on a bottom bracket  27  to rotate the front multi-stage sprocket assembly  20 . The rear multi-stage sprocket assembly  16  has a plurality of sprockets or gears  16   a  that are arranged in a conventional manner. The front multi-stage sprocket assembly  20  has a plurality of sprockets or gears  20   a  that are arranged in a conventional manner. In the illustrated embodiment, the front multi-stage sprocket assembly  20  has two sprockets or gears  20   a.    
     The front derailleur assembly  22  basically includes a front derailleur  28  and a shift assisting apparatus  30 . The front derailleur  28  is preferably a conventional front derailleur that is cable operated. An electronic control system  31  basically operates the shift assisting apparatus  30 , which in turn operates the front derailleur  28 . The shift assisting apparatus  30  utilizes power from the drive train  12  to move the front derailleur  28  between a first shift position and a second shift position as explained below in more detail. 
     The electronic control system  31  basically includes a shift control unit or cycle computer  32  and a pair of shifting devices  34   a  and  34   b . The shift control unit  32  is electrically coupled to the motorized derailleur assemblies  18  and  22  by an electrical control cord  36 . The shift control unit  32  is also electrically coupled to the shifting devices  34   a  and  34   b  via the electrical cords  38   a  and  38   b , respectively. It will be apparent to those skilled in the art from this disclosure, the electronic control system  31  can also be utilized to control other electronically operated components such as the front and rear suspension and/or other components of the bicycle. 
     The shift control unit or cycle computer  32  preferably includes a microcomputer formed on a printed circuit board that is powered by a battery unit. The microcomputer of the shift control unit  32  includes a central processing unit (CPU), a random access memory component (RAM), a read only memory component (ROM), and an I/O interface. The various components of the microcomputer are well known in the bicycle field. Therefore, the components used in the microcomputer of the shift control unit  32  will not be discussed or illustrated in detail herein. Moreover, it will be apparent to those skilled in the art from this disclosure that the shift control unit  32  can include various electronic components, circuitry and mechanical components to carryout the present invention. Of course, it will be apparent to those skilled in the art from this disclosure that the shift control unit  32  can have a variety of configurations, as needed and/or desired. 
     Preferably, the shift control unit  32  is a cycle computer that provides or displays various information to the rider via a display and that operates the motorized derailleur assemblies  18  and  22 . Thus, the drive train  12  of the bicycle  10  is operated or electronically controlled by the shift control unit  32 . More specifically, the shift control unit  32  is a cycle computer that electrically operates the motorized derailleur assemblies  18  and  22  either automatically or manually as explained below. One example of an automatic shifting assembly that can be adapted to be used with the present invention is disclosed in U.S. Pat. No. 6,073,061 to Kimura, which is assigned to Shimano Inc. 
     In the manual mode, shifting of each of the motorized derailleur assemblies  18  and  22  is preformed by via manually shifting the shift devices  34   a  and  34   b . Depressing one of the shift buttons of the shift devices  34   a  and  34   b  generates a predetermined operational command that is received by the central processing unit of the shift control unit  32 . The central processing unit of the shift control unit  32  then sends a predetermined operational command or electrical signal to move or shifting one of the motorized derailleur assemblies  18  and  22 . 
     In the automatic mode, shifting of each of the motorized derailleur assemblies  18  and  22  is preferably at least partially based on the speed of the bicycle. Thus, the shift control unit  32  further includes at least one sensing/measuring device or component  42  that provides information indicative of the speed of the bicycle  10  to its central processing unit of the shift control unit  32 . The sensing/measuring component  42  generates a predetermined operational command indicative of the speed of the bicycle  10 . Of course, additional sensing/measuring components can be operatively coupled to central processing unit of the shift control unit  32  such that predetermined operational commands are received by the central processing unit (CPU) of the shift control unit  32  to operate the motorized derailleur assemblies  18  and  22  or other components. 
     The sensing/measuring component  42  can be, for example, a speed sensing unit that includes a sensor  44  and a magnet  45 . The sensor  44  is preferably a magnetically operable sensor that is mounted on the front fork of the bicycle  10  and senses the magnet  45  that is attached to one of the spokes of the front wheel of the bicycle  10 . The sensor  44  can be a reed switch or other component for detecting the magnet  45 . Sensor  44  generates a pulse each time wheel of the bicycle  10  has turned a pre-described angle or rotation. In other words, the sensor  44  detects the rotational velocity of the front wheel of the bicycle  10 . As soon as sensor  44  generates the pulse or signal, a pulse signal transmission circuit sends this pulse signal to the central processing unit of the shift control unit  32  to determine whether the chain  24  should be up shifted or down shifted. Thus, the sensor  44  and the magnet  45  form a sensing device or measuring component of the shift control unit  32 . In other words, the sensor  44  outputs a bicycle speed signal by detecting a magnet  45  mounted on the front wheel of the bicycle  10 . Thus, speed information is sent to the battery operated electronic shift control unit  32  to operate the motorized derailleur assemblies  18  and  22 . 
     Referring to FIG. 3, the front derailleur  28  fixedly coupled to the bottom bracket  27  of the bicycle frame  14 . While the front derailleur  28  is illustrated as being fixedly coupled to the bottom bracket  27   b  of the bicycle frame  14 , it will be apparent to those skilled in the art from this disclosure that front derailleur  28  can be coupled to other parts of the bicycle such as the seat post as needed and/or desired. The front derailleur  28  is operated by the shift control unit  32  to move the chain  24  between sprockets  22   a . More specifically, the rider pushes one of the buttons on the shifting devices  34   b  that activates the shift assisting apparatus  30  which in turn moves the front derailleur  28  between its shift positions. 
     Still referring to FIG. 3, the front derailleur  28  basically includes a fixed mounting member  50 , a chain guide  52  and a linkage assembly  54  coupled between fixed member  50  and chain guide  52 . A cable  56  or wire is fixedly coupled between the shift assisting apparatus  30  and an operating arm or lever  58  of the linkage assembly  54 . Thus, the shift assisting apparatus  30  operates the front derailleur  28  by pulling or releasing the operating wire  56  to move the chain guide  52  from a retracted (low gear) position to an extended (high gear) position. Linkage assembly  54  is preferably designed such that a biasing member (torsion spring) normally biases chain guide  52  in a transverse direction towards the frame  14  of bicycle  10 . In other words, when chain guide  52  is closest to the frame of bicycle  10 , the chain guide  52  holds the chain  24  over the sprocket (low gear)  20   a  that is closest to the bicycle frame  14 . 
     The shift assisting apparatus  30  includes an actuator  60  that operates a power transfer mechanism  62  such that the rotational force of the crank arm  26   a  pulls or releases the operating wire  56  of the front derailleur  28 . The actuator  60  is operatively coupled to the shift control unit  32  via the electrical control cord  36  and to the shifting device  34   b  via the electrical cord  38   b  for receiving the upshift signal and the down shift signal. The actuator  60  is operatively coupled to the power transfer mechanism  62 , which operates the front derailleur  28 . The power transfer mechanism  62  is operatively coupled to the crank arm  26   a  as explained below. 
     As seen in FIGS. 10-14, the actuator  60  basically includes a housing  70  with a motor  72  and a gear drive  74  mounted therein. The housing  70  is mounted to the rear or inside surface of the power transfer mechanism  62  via bolts (not shown) such that the gear drive  74  operates the power transfer mechanism  62 . 
     The motor  72  of the actuator  60  is electrically connected by a pair of wires  83  of the cord  36  to the shift control unit  32  which has a microcomputer  80  with a motor driver circuit  82  and an overcurrent detecting circuit  84  which are both operatively coupled to the central processing unit of the microcomputer  80 . The power source or battery  86  is also located in the shift control unit  32 , and is operatively coupled to the motor  72  via the motor driver circuit  82  and the overcurrent detecting circuit  84 . The central processing unit of the microcomputer  80 , the motor driver circuit  82  and the overcurrent detecting circuit  84  operate together to stop the movement of the motor  72  upon detection of the motor  72  locking up. As seen in FIGS. 6 and 7, the microcomputer  80  has a control program which receives an overcurrent signal from the overcurrent detecting circuit  84  for controlling the operation of the motor  72 . More specifically, when the rider pushes a button on the shifting device  34   b  to start a shifting operation, the microcomputer  80  will then send a signal to the motor driver circuit  82  to have the power source or battery  86  energize the motor  72  in the desired direction. The motor  72  is preferably a reversible motor that can be driven in either a clockwise or a counterclockwise direction so as to move the derailleur  28  between first and second shift positions. The overcurrent detecting circuit  84  will stop energizing the motor  72  when the derailleur  28  reaches the new position. In other words, when the motor  72  locks up, this will increase the current level such that an overcurrent signal is sent from the overcurrent detecting circuit  84  back to the central processing unit of the microcomputer  80  to stop the electricity from energizing the motor  72 . 
     As seen in FIG. 9, the overcurrent detecting circuit  84  has a comparator  90  that compares the voltage being inputted into the motor driver circuit  82  with a predetermined voltage Vcc. If the voltage in the motor driver circuit  82  becomes greater than the predetermined voltage Vcc, then the comparator  90  will send a signal to the central processing unit of the microcomputer  80  to send a motor control signal to the motor driver circuit  82  which will stop the flow of current to the motor  72 . 
     Referring now to FIGS. 10-14, the gear drive  74  of the actuator  60  will now be discussed in more detail. The gear drive  74  includes four power transfer gears  91 - 94  that transmits the rotation from the motor output gear  72   a  to driving gear  95 . The driving gear  95  is coupled to a drive axle  96  for rotating drive axle  96  in either a clockwise or counterclockwise depending upon the direction of rotation of the gear  72   a . Preferably, the drive gear  95  and the drive axle  96  have a small amount of rotational play therebetween. This rotational play is taken up by a torsion spring  98 . This arrangement is designed to protect the gears from breaking when the motor  72  locks up but the energy to the motor  72  has not been discontinued. Moreover, the gears  91 - 95  cannot stop immediately due to inertia, thus, the torsion spring  98  further protects the gears from breaking. This torsion spring  98  also protects the gears  91 - 95  in the case of a double shift when the rider performs a second shift before the first shift is completed. The drive axle  96  has a center bore  96   a  that is coupled to the power transfer mechanism  62  as discussed below. Preferably, the bore  96   a  has a noncircular cross section. 
     Referring back to FIGS. 3 and 4, the bottom bracket  27  is operatively coupled to the shift assisting apparatus  30  according to the present invention for shifting a bicycle transmission or drive train  12 . The general structure of the bottom bracket  27  is well known in the bicycle art, so a detailed description of those components shall be omitted. As discussed in more detail below, the shift assisting apparatus  30  upshifts a front derailleur  28  by moving an operating lever  58  clockwise and then downshifts front derailleur  28  by moving the operating lever  58  counterclockwise. Operating lever  58  is moved by the operating wire  56  coupled to the shift assisting apparatus  30  which, in turn, is connected to shift device  34   b  of the shifting control unit  32  located on the handlebar. 
     The power transfer mechanism  62  basically includes a drive ring  10  fixedly secured to the right crank arm  26   a  and a driven member  102  fixed to the outer sleeve  27   a  of the bottom bracket  27 . Thus, the drive ring  100  rotates with the right crank arm  26   a , while the driven member  102  is non-rotatably fixed to frame  14  by the bottom bracket  27 . In this embodiment, the front derailleur  28  and the power transfer mechanism  62  both coupled to the bottom bracket  27 . Alternatively, the driven member  102  of the power transfer mechanism  62  can act as the base member of front derailleur  28 , if needed and/or desired. 
     Referring to FIG. 4, a perspective view of the power transfer mechanism  62  is illustrated with the derailleur  28  and the crank arm  26   a  removed. The drive ring  100  is shown with a smooth inner peripheral surface  104  that is press-fitted on to the inner end of the crank arm  26   a . Of course, the inner peripheral surface  104  can have splines that mate with corresponding splines of the crank arm  26   a . Alternatively, the drive ring  100  can be fixed to the axle  27   b  of the bottom bracket  27 . The outer peripheral surface of the drive ring  100  forms a pair of drive projections  106  with abutment surfaces  108 . The abutment surfaces  108  are disposed 180° from each other and facing in the forward direction of rotation of the bottom bracket  27  and the crank arm  26   a . In other words, the abutment surfaces  108  face in the clockwise direction in FIG.  4 . The abutment surfaces  108  follow an imaginary straight line extending radially outwardly from the axis of rotation Y of the bottom bracket  27 . The outer peripheral surface of the drive ring  100  at the location of intersection with the abutment surfaces  108  extends clockwise in FIG. 4 at a constant radius of curvature for more than 20° and, in this embodiment, more than 45° until it nears the rear of the following the drive projection  106 , whereupon the radius of curvature increases in a non-curvature manner to the tip of the projection  106 . In this embodiment, the outer peripheral surface of the drive ring  100  forms a flat ramp up to the tip of the corresponding projection, but it could be arcuate as well. As seen clearly in FIG. 4, the drive projections  106  extend only slightly from the outer peripheral surface of the drive ring  100 . As shown FIGS. 16-21, the drive ring  100  will be illustrated as being an integrally part of the axle  27   b  of the bottom bracket  27  to help understand the operation of the device. 
     The driven member  102  basically includes a mounting member  526 , an accurate operating lever  530 , a cam ring or member  604 , a cam follower  612 , a first coupling member  654  and a second coupling member  656 . 
     An accurate operating lever  530  has a first end pivotally connected to the mounting member  526  through a pivot shaft  534  for pivoting around an operating axis W. The pivot shaft  534  has one end received in the bore  96   a  of the drive axle  96  of the actuator  60 . Thus, the motor  72  rotates the pivot shaft  534  to operate the power transfer mechanism  62 . The operating lever  530  has a limited range of movement which stops or locks the motor  72  from operating in both directions. The two locker stop positions are shown in FIGS. 16 and 17. When the operating lever  530  moves between FIGS. 16 and 17, then the first control ledge  542  allows the first pawl  670  to engage a drive ring  100 . Then, the electrical step is finished. An overcurrent occurs and the overcurrent detecting circuit  84  stops electricity to the motor  72 . When the operating lever  530  moves back to the position in FIG. 16, the operating lever  530  hits the mounting member  526 . Then, the electrical step is finished. An overcurrent occurs in motor  72  and the overcurrent detecting circuit  84  stops electricity to the motor  72 . A spring  535  is disposed around the pivot shaft  534  and is connected between the mounting member  102  and the operating lever  530  for biasing the operating  530  in the counterclockwise direction. A first control projection  538  extends radially inwardly from an intermediate portion of the operating lever  530  and terminates with a laterally inwardly extending the first pawl control ledge  542  (FIG. 16) having a radially outwardly facing first pawl control surface  544 . Similarly, a second control projection  548  extends radially inwardly from the second end of operating lever  530  and terminates with a laterally inwardly extending second pawl control ledge  552  having a radially inwardly facing a second pawl control surface  554 . 
     FIGS. 15A and 15B show the mounting member  110  in more detail. The mounting member  526  includes a first ledge opening  562  for receiving the first pawl control ledge  542  therethrough, a second ledge opening  566  for receiving the second pawl control ledge  552  therethrough, and a pawl control groove  570  formed by a radially outwardly facing pawl control surface  574  and a radially inwardly facing pawl control surface  578 . The pawl control surface  574  has a generally circular shape, except for a first control ledge passage  582 , for allowing radially inward movement of first control ledge  542 , a pawl decoupling ramp  586  and a pawl decoupling ramp  590 . Similarly, the pawl control surface  578  has a generally circular shape, except for a second control ledge passage  594 , for allowing radially outwardly movement of the second control ledge  552 , a pawl decoupling ramp  596  and a pawl decoupling ramp  598 . The functions of pawl decoupling rams  586 ,  590 , and  598  will be discussed below. 
     As shown in FIG. 16, a cam member  604  having a cam surface  608  is mounted to the mounting member  526  for rotation around the axis Y shown in FIG. 4. A cam follower  612  has the form of a two-piece lever ( 612 A,  612 B) wherein a first end of lever piece  612 A is pivotally mounted to the mounting member  526  through a pivot shaft  616  and a second end of lever piece  612 A includes a roller  620  for engaging the cam surface  608 . The pivot shaft  616  extends through the side of the mounting member  526  and is coupled to a first end of the lever piece  612 B. A second end of the lever piece  612 B contains a transmission actuating coupling member in the form of an opening  626  for receiving a derailleur actuating wire  630  therethrough. The derailleur actuating wire  630  has a wire end bead  634  for preventing the derailleur actuating wire  630  from being pulled upwardly out of the opening  626 . 
     The first coupling member  654  is coupled for rotation of the cam member  604 , such that the first coupling member  654  moves between a first engaged position and a first disengaged position. The second coupling member  656  is coupled for rotation of the cam member  604 , such that the second coupling member  656  moves between a second engaged position and a second disengaged position. 
     The first coupling member  654  comprises a first pawl  670  and a first pawl mounting member  674 . A first end of the first pawl  670  is pivotally connected to the first pawl mounting member  674  through a first pivot shaft  678 , and a second end of first pawl  670  has a radially inwardly extending first pawl tooth  682  and a first pawl control abutment  684 . The first pawl mounting member  674  is fixedly coupled to the cam member  604  by a screw  686 . A first biasing mechanism in the form of a first leaf spring  688  has a first end  690  fixedly coupled to the cam member  604  and a second end  694  abutting against the second end of the first pawl  670 . The first leaf spring  688  biases the first pawl tooth  682  radially inwardly to a first engaged position such that the first pawl  670  engages either of the two abutment surfaces  108  of the drive ring  100  as discussed below. 
     Similarly, the second coupling member  656  comprises a second pawl  700  and a second pawl mounting member  704 . An intermediate portion of second pawl  700  is pivotally connected to the second pawl mounting member  704  through a second pivot shaft  708 . A first end of second pawl  700  has a radially inwardly extending second pawl tooth  712 , and a second end of second pawl  700  has second pawl control abutment  714 . The second pawl mounting member  704  is fixedly coupled to the cam member  604  by a screw  716 . A second biasing mechanism in the form of a second leaf spring  718  has a first end  722  fixedly coupled to the cam member  604  and a second end  724  abutting against the first end of the second pawl  700 . The second leaf spring  718  biases the second pawl tooth  712  radially inwardly to a second engaged position such that the second pawl  700  engages either of the two abutment surfaces  108  of the drive ring  100  as discussed below. 
     The operation of the shift assisting apparatus  30  may be understood by referring to FIGS. 16-20. FIG. 16 shows the shift assisting apparatus  30  in a steady-state idle condition. In this initial condition, the first pawl control surface  544  of the first pawl control ledge  542  supports the first pawl control abutment  684  so that the first pawl tooth  682  is held radially outwardly in the first disengaged position, and the pawl decoupling ramp  598  presses the second pawl control abutment  714  radially inwardly so that the second pawl tooth  712  is held radially outwardly in the second disengaged position. Thus, the drive ring  100  rotates together with the axle  27   b  without having any effect on the shift assisting apparatus  30 . 
     FIG. 17 shows what happens when the drive axle or pivot shaft  534  is rotated in the clockwise direction is pulled upwardly. In this case, the operating lever  530  pivot clockwise with the pivot shaft  534  against the biasing force of the spring  535 , and the first pawl control ledge  542  allows the first pawl control abutment  684  to move radially inwardly. As a result, the first pawl  670  rotates counterclockwise in accordance with the biasing force of the first leaf spring  688 , thus moving the first pawl tooth  682  radially inwardly into the first engaged position. Thus, when one of the abutment surfaces  108  of the drive ring  100  rotates to the circumferential position of the first pawl  670 , the first pawl tooth  682  contacts the abutment, and the cam member  604  rotates clockwise together with the drive ring  100  and the axle  27   b  to the position shown in FIG.  18 . At the same time, the second pawl control abutment  714  slides off of the pawl decoupling ramp  598 , and the second pawl  700  rotates counterclockwise around the pivot shaft  708  in accordance with the biasing force of the second leaf spring  718  so that the second pawl tooth  712  moves radially inwardly into the second engaged position to contact the other one of the abutments  108 . 
     The cam surface  608  has an increasing radius in the counterclockwise direction, so the roller  620  on the lever piece  612 A moves radially outwardly, thus causing the lever piece  612 B to pull the actuating wire  630  downwardly. Clockwise rotation of the cam member  604  continues until the cam surface  608  causes the cam follower  612  to nearly complete the necessary amount of pulling of the derailleur actuating wire  630  as shown in FIG.  18 . At this time, the first pawl control abutment  684  is near the pawl decoupling ramp  590  and the second pawl control abutment  714  slides up the pawl decoupling ramp  596  (rotating the second pawl  700  clockwise), contacts the second pawl control surface  554  of the second pawl control ledge  552  and disengages the second pawl tooth  712  from abutment surface  108 . Also, the roller  620  on the lever piece  612 A is disposed immediately counterclockwise of a the cam ridge  730  on the cam  604 . 
     As shown in FIG. 19, as the cam member  604  continues to rotate, the first pawl control abutment  684  slides up the pawl decoupling ramp  590  so that the first pawl  670  rotates clockwise and moves the first pawl tooth  682  into the first disengaged position. Also, the second pawl control abutment  714  moves to the clockwise end of the second pawl control surface  554 . The radially inward force applied by the roller  620  to the cam ridge  730  ensures that the cam member  604  rotates slightly clockwise so that the first pawl control abutment  684  is properly positioned on the pawl decoupling ramp  590  and the first pawl tooth  682  is disengage from the abutment surface  108 . At that time, the cam member  604  stops rotating and the derailleur actuating wire  630  is maintained in the upshifted position. 
     To release the actuating wire  630  to shift the bicycle transmission into the downshifted position, the pivot shaft  3534  is released as shown in FIG.  20 . In this case, the operating lever  530  pivots counterclockwise around pivot shaft  534  in accordance with the biasing force of the spring  535 , and the second pawl control ledge  552  allows the second pawl control abutment  714  to move radially outwardly. As a result, the second pawl  700  rotates counterclockwise around the pivot shaft  708  in accordance with the biasing force of the second leaf spring  718 , thus moving the second pawl tooth  712  into the second engaged position. Thus, when one of the abutment surfaces  108  of the drive ring  100  rotates to the circumferential position of the second pawl  700 , the second pawl tooth  712  contacts one of the abutment surfaces  108 , and the cam member  604  rotates clockwise together with the drive ring  100  and the axle  27   b  to the position shown in FIG.  21 . At the same time, the first pawl control abutment  684  slides off of the pawl decoupling ramp  590 , and the first pawl  670  rotates counterclockwise around the pivot shaft  678  in accordance with the biasing force of the first leaf spring  688  so that the first pawl tooth  682  moves radially inwardly into the first engaged position to contact the other one of the abutment surfaces  108 . 
     This portion of the cam surface  608  contacting the roller  620  has a decreasing radius in the counterclockwise direction, so the roller  620  on the lever piece  612 A moves radially inwardly, thus causing the lever piece  612 B to release the derailleur actuating wire  630 . Clockwise rotation of the cam member  604  continues until the cam surface  608  causes the cam follower  612  to nearly complete the necessary amount of releasing of the actuating wire  630  as shown in FIG.  21 . At this time, the second pawl control abutment  714  is near the pawl decoupling ramp  598 , and the first pawl control abutment  684  slides up the pawl decoupling ramp  586  (thus rotating the first pawl  670  clockwise), contacts the first pawl control surface  544  of the first pawl control ledge  542  and disengages the first pawl tooth  682  from one of the abutment surfaces  108 . Also the roller  620  on the cam follower lever  612  is disposed immediately counterclockwise of a cam ridge  734  on the cam  604 . 
     As the cam member  604  continues to rotate, the second pawl control abutment  714  slides up the pawl decoupling ramp  598  so that the second pawl  700  rotates clockwise to move the second pawl tooth  712  into the second disengaged position, and the first pawl control abutment  684  moves to the clockwise end of the first pawl control surface  544 . The radially inward force applied by the roller  620  to the cam ridge  734  ensures that the cam member  604  continues rotating until the second pawl control abutment  714  is properly positioned on the pawl decoupling ramp  598  and the second pawl tooth  712  is disengaged from the abutment surface  108 . At that time, the cam member  604  stops rotating, and the actuating wire  630  is maintained in the upshifted position as shown by the initial position in FIG.  16 . 
     Front Suspension Assembly 
     Referring now to FIGS. 22-23, a bicycle  10 ′ is illustrated with an electronically controlled front suspension assembly  12 ′ in accordance with a second embodiment. Basically, the method of controlling the drive train  12  of the first embodiment is now being used to control the front suspension assembly  12 ′. In view of the similarity between the first and second embodiments, the second embodiment will not be discussed or illustrated in detail. 
     The bicycle  10 ′ basically has a frame  14 ′ and a pair of wheels  15 ′ (only one shown), with the front wheel being coupled to the frame  14 ′ by the front suspension assembly  12 ′. The bicycle  10 ′ and its various components are well known in the prior art, except for the improved portions of the front suspension assembly  12 ′ of the present invention. Thus, the bicycle  10 ′ and its various components will not be discussed or illustrated in detail herein, except for the components that relate to the front suspension assembly  12 ′ of the present invention. Moreover, various conventional bicycle parts such as brakes, additional sprockets, etc., which are not illustrated and/or discussed in detail herein, can be used in conjunction with the present invention. 
     An electronic control system  31 ′ basically controls the stiffness of the front suspension assembly  12 ′. Preferably, the electronic control system  31 ′ is programmable either by the rider or by the bicycle manufacturer such that the stiffness of the front suspension assembly  12 ′ will be adjusted based on one or more of the various parameters that have been sensed and/or calculated. In other words, the amount of stiffness can be modified based on one or more parameters, such as inclination of the bicycle  10 ′, current torque, gear selection, speed, etc. Moreover, it is within the scope of this invention for the rider to program which variables will increase or decrease the stiffness of the suspension assembly  12 ′. The front suspension assembly  12 ′ will either stiffen or soften accordingly based on the signals received from the electronic control system  31 ′. 
     The electronic control system  31 ′ utilizes a plurality of sensors such as a velocity sensor  42 ′ to determine when to electronically adjust the front suspension assembly  12 ′ in response to various factors or conditions. These sensors are electrically coupled to the electronic control system  31 ′ by electrical wires in a conventional manner for inputting various electrical signals, which are indicative of certain conditions. The signals from the sensors are preferably electrical signals that are utilized by the electronic control system  31 ′ to calculate various conditions affecting the bicycle  10 ′. Of course, more or other types of sensors can be used as necessary depending on the type of suspension assemblies used and/or the factors/conditions desired for adjusting the stiffness of the front suspension assembly  12 ′. 
     For the sake of simplicity, only one of the cylinders or shocks  50 ′ from the front suspension assembly  12 ′ will be discussed and illustrated herein. It will be apparent to those skilled in the art from this disclosure that a pair of cylinders or shocks  50 ′ are utilized to form the front suspension assembly  12 ′. As seen in FIG. 23, each cylinder  50 ′ basically includes outer and inner tubular telescoping members  51 ′ and  52 ′ defining inner cavities  53 ′,  54 ′ and  55 ′ in the cylinder  50 ′. The outer tubular member  51 ′ is coupled to the front wheel  15 ′ by a mounting member  56 ′, while the inner tubular member  52 ′ is coupled to the frame  14 ′ by a mounting member  57 ′. The outer tubular member  51 ′ has the lower hydraulic cavity that receives the bottom end  52   a ′ of the inner tubular member  52 ′. The bottom end  52   a ′ of the inner tubular member  52   a ′ forms a piston that has a plurality of orifices  58 ′. The orifices  58 ′ fluidly couple the inner hydraulic cavities  53 ′ and  54 ′ together such that hydraulic fluid flows from the lower hydraulic cavity  53 ′ to the upper hydraulic cavity  54 ′ formed by a portion of the inner tubular member  52 ′. The inner tubular member  52 ′ also has the air cavity or chamber  55 ′ formed above the upper hydraulic cavity  54 ′. 
     The air chamber  55 ′ and upper hydraulic cavity  54 ′ are separated by an axially slidable piston  59 ′. Within the air chamber  55 ′ is a coil spring  60 ′. The stiffness of the cylinder  50  is controlled by changing the size of the orifices  58 ′ utilizing a control disk  61 ′ that is rotatably mounted to change the size of the orifices  58 ′. In other words, the control disk  61 ′ is moveable to change the amount of overlapping or closing of the orifices  58 ′. Preferably, the control disk  61 ′ of the cylinder  50 ′ is controlled by a electric motor  72 ′ that rotates the control disk  61 ′. The electric motor  72 ′ is electrically coupled to the electronic control system  31 ′ that selectively operates the electrical motor  72 ′ to adjust the stiffness of the cylinder  50 ′. Thus, the orifices  58 ′ and the control disk  61 ′ form a front cylinder control valve  63 ′ that is automatically adjusted via the electronic control system  31 ′. The electric motors  72 ′ and the front cylinder control valves  63 ′ of the cylinders  50 ′ form a front controller or adjustment mechanism that changes or adjusts the stiffness or softness of the front suspension assembly  12 ′ based on the electronic control system  31 ′. Of course, it will be apparent to those skilled in the art from this disclosure that other types of adjustment mechanisms can be utilized for controlling the stiffness of the cylinder  50 ′. 
     As seen in FIGS. 24 and 25, the electronic control system  31 ′ is a control unit or cycle computer that a microcomputer  80 ′ formed on a printed circuit board that is powered by a battery unit. The microcomputer of the electronic control system  31 ′ includes a central processing unit (CPU), a random access memory component (RAM), a read only memory component (ROM), and an I/O interface. The various components of the microcomputer are well known in the bicycle field. Therefore, the components used in the microcomputer of the electronic control system  31 ′ will not be discussed or illustrated in detail herein. Moreover, it will be apparent to those skilled in the art from this disclosure that the electronic control system  31 ′ can include various electronic components, circuitry and mechanical components to carryout the present invention. Of course, it will be apparent to those skilled in the art from this disclosure that the electronic control system  31 ′ can have a variety of configurations, as needed and/or desired. 
     The motors  72 ′ are controlled according to the program illustrated in FIG.  6 . In other words, the electronic control system  31 ′ energizes the motors  72 ′ which in turn causes the control disk  61  of each of the cylinders  50 ′ to rotate. Once the control disk  61 ′ reaches an end position, the control disk stops and the motor locks. The locking of the motor  72 ′ causes an overcurrent to occur such that the overcurrent detecting circuit  84 ′ stops the motor  72 ′. 
     The motor  72 ′ is electrically connected by a pair of wires to the electronic control system  31 ′ which has a microcomputer  80 ′ with a motor driver circuit  82 ′ and an overcurrent detecting circuit  84 ′ which are both operatively coupled to the central processing unit of the microcomputer  80 ′. The power source or battery  86 ′ is also located in the electronic control system  31 ′, and is operatively coupled to the motor  72 ′ via the motor driver circuit  82 ′ and the overcurrent detecting circuit  84 ′. The central processing unit of the microcomputer  80 , the motor driver circuit  82 ′ and the overcurrent detecting circuit  84 ′ operate together to stop the movement of the motor  72 ′ upon detection of the motor  72 ′ locking up. As seen in FIGS. 24 and 25, the microcomputer  80 ′ has a control program, which receives an overcurrent signal from the overcurrent detecting circuit  84 ′ for controlling the operation of the motor  72 ′. More specifically, the microcomputer  80 ′ will then send a signal to the motor driver circuit  82 ′ to have the power source or battery  86 ′ energize the motor  72 ′ in the desired direction. The motor  72 ′ is preferably a reversible motor that can be driven in either a clockwise or a counterclockwise direction so as to move the control disk  61 ′ between first and second shift positions. The overcurrent detecting circuit  84 ′ will stop energizing the motor  72 ′ when the control disk  61 ′ reaches the new position. In other words, when the motor  72 ′ locks up, this will increase the current level such that an overcurrent signal is sent from the overcurrent detecting circuit  84 ′ back to the central processing unit of the microcomputer  80 ′ to stop the electricity from energizing the motor  72 ′. 
     As seen in FIG. 25, the overcurrent detecting circuit  84 ′ has a comparator  90 ′ that compares the voltage being inputted into the motor driver circuit  82 ′ with a predetermined voltage Vcc. If the voltage in the motor driver circuit  82 ′ becomes greater than the predetermined voltage Vcc, then the comparator  90 ′ will send a signal to the central processing unit of the microcomputer  80  to send a motor control signal to the motor driver circuit  82 ′ which will stop the flow of current to the motor  72 ′. 
     Alternative Motor Control Method 
     Referring now to FIGS. 26-28, an alternative method of controlling the motors  72  and/or  72 ′ will now be discussed. In this alternative embodiment, the overcurrent detecting circuit  84  or  84 ′ is not used every time to control the stopping of the motors  72  or  72 ′. 
     Rather, the overcurrent detecting circuit  84  or  84 ′ is only utilized one time for every one hundred shifts or suspension adjustments. In this method the microprocessor  80  or  82 ′ measures the time period that the motor  72  or  72 ′ is energized until an overcurrent occurs. This time period of energization is then utilized to calculate an energization time A for future shifts or suspension adjustments. Preferably, the time period of energization A for subsequent shifts or suspension adjustments is less than the time of the initial energization in which an overcurrent was utilized to stop the motor  72  or  72 ′. More specifically, the time period of energization A should be shorter than the measured time period that the motor  72  or  72 ′ is energized until an overcurrent occurs, because the motor  72  or  72 ′ will continue to move after the electricity is shut off due to the inertia of the motor  72  or  72 ′. Accordingly, the inertia can be utilized to complete the movement of the derailleur  28  or the control disc  61 ′. Since the stopping position or stopping timing will change due to the changing of motor load, temperature, battery power, etc., after a certain predetermined period, the microprocessor  80  or  80 ′ will again measure the time between starting the motor  72  or  72 ′ and an overcurrent, (for example one time for every hundred shifts or suspension adjustments) and then use this time to calculate a new time period of energization A for future adjustments. 
     The motor  72  or  72 ′ is controlled according to the program illustrated in FIG.  26 . In other words, the first time electronic control system  31 ′ energizes the motors  72 ′ which in turn causes the derailleur  28  to move or the control disk  61  of each of the cylinders  50 ′ to rotate. Once the derailleur  28  or the control disk  61 ′ reaches an end position, the derailleur  28  or the control disk  61 ′ stops and the motor  72  or  72 ′ locks. The locking of the motor  72  or  72 ′ causes an overcurrent to occur such that the overcurrent detecting circuit  84  or  84 ′ stops the motor  72  or  72 ′. 
     The next time the motor  72  or  72 ′ are energized, the motor  72  or  72 ′ is energized for a shorter period of time which is calculated from measuring time that the motor  72  or  72 ′ is energized until an overcurrent occurs. The motor  72  or  72 ′ will be energized for the time period of energization A, which will stop the motor  72  or  72 ′ before the derailleur  28  or the control disk  61 ′ reaches an end position. Thus, no overcurrent will occur in the motor  72  or  72 ′. Since the motor  72  or  72 ′ cannot stop immediately because of inertia, the derailleur  28  or the control disk  61 ′ will continue to move to the end position under the power of inertia from the motor  72  or  72 ′. This will save battery energy as well as protect the parts of the device be controlled. As mentioned above, the stopping position or stopping timing will change due to the changing of motor load, temperature, battery power, etc., after a certain predetermined period. Thus, the microprocessor  80  or  80 ′ will again measure the time between starting the motor  72  or  72 ′ and an overcurrent, (for example one time for every hundred shifts or suspension adjustments) and then use this measured time period to calculate a new time period of energization A for future adjustments. 
     The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms should be construed as including a deviation of at least±5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
     While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. For example, the drive projections also may be formed directly on the lateral side wall or the outer peripheral surface of the crank axle mounting bosses and project laterally inwardly. The size, shape, location or orientation of the various components may be changed as desired. The functions of one element may be performed by two, and vice versa. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the scope of the invention is not limited to the disclosed embodiments.