Abstract: A selection system of a transmission gear in bicycles, comprising a central supporting axle of a wheel of a bicycle associated with a pair of forks of the bicycle; a cogset associated rotatable and axially sliding with the central supporting axle; a movement device/unit/component/mechanism (or the like) of the cogset on the central supporting axle; wherein the central supporting axle comprises a first end associated in a removable manner with a first fork and a second end associated axially sliding with a second fork, the central supporting axle being movable sliding with respect to the forks between a working position, wherein it is interposed between them, and a disassembly position, wherein it is at least partly pulled out of them through the second fork for the removal/assembly of the wheel.

Abstract: A bicycle derailleur structure is mounted on a bicycle frame to correspond to a flywheel unit and includes a support arm, a screw rod, a tension bar, a gear shift unit. and a drive unit. The tension bar has an end having an interior space receiving an elastic member therein to be mounted on the support arm in an elastically oscillating manner. The gear shift unit includes two protector plates in threading engagement with screw rod, and first and second pulleys arranged between the two protector plates. The screw rod is operable to drive the gear shift unit in order to align a chain on the flywheel unit to align with the gear shift unit.

Abstract: A sprocket assembly (1) to be mounted on a driver body (4) of a bicycle wheel with a truncated cone shell (2) having a first opening (21) in its small base and a second opening (22) in its large base, both openings being coaxial with the central axis (10) of said shell; a plurality of toothed sprockets (20) having different numbers of teeth for engagement with a chain; an axial fixing member (23), a radial load transmission profile (24) and a toothed torque transmission profile (25); wherein the truncated cone shell (2), the toothed sprockets (20), the axial fixing member (23), the radial load transmission profile (24) and the toothed torque transmission profile (25) are configured in a single piece; being the axial fixing member (23), the radial load transmission profile (24) and the toothed torque transmission profile (25) all disposed towards the inside of the truncated cone shell (2).

Abstract: A bicycle control system may be configured to automatically control a bicycle, or components thereof. The bicycle control system may include a system control device configured to provide a simplified shifting system wherein large changes in speed associated with starting and stopping do not require the full attention of the automatic shifting system. The shifting system, or a system control device configured for controlling the shifting system, may be configured to determine when to enter an automatic shifting control mode, establish parameters for the automatic shifting of the automatic shifting control mode, and/or compare detected activities and values of the bicycle to the established parameters.

Abstract: A system including: a seat post; a user interface operatively connected with the seat post, the user interface configured for receiving instructions associated with a height of the seat post and for communicating received instructions to at least one controller coupled with a motive source of the seat post; and a valve assembly in communication with the motive source, the valve assembly regulating fluid flow within a variable finite positioning seat post height mode in response to a translation of the received instructions by the motive source.

Abstract: A wireless control system for engagement with a transmission system for a servomotor coupled with sprocket assemblies of remote controlled systems, and within vehicles, including bicycles, is disclosed. The system selectively shifts a chain to each of a plurality of provided sprockets reduces various complications associated with cable slack and precision shifting among an ordered sequence sprockets. The wireless control system allows a user to direct a derailleur to translate drive means from one position to another along a desired path.

Abstract: An electronic shifting device and a bicycle using the same are provided. The electronic shifting device includes a primary controller, a first electronic derailleur unit, a second electronic derailleur unit, a cable, a main power supply and a first control unit. The first electronic derailleur unit is disposed adjacent to a first sprocket set, and the second electronic derailleur unit is disposed adjacent to a second sprocket set. The first electronic derailleur unit and the second electronic derailleur unit are configured to move a chain between a plurality of sprockets. The cable electrically connects the primary controller, the first electronic derailleur unit and the second electronic derailleur unit. The main power supply provides electrical power to the primary controller, the first electronic derailleur unit and the second electronic derailleur unit by the cable. The first control unit is configured for wirelessly transmitting a first control signal to the primary controller.

Abstract: A bicycle rear derailleur is provided, which includes a base adapted to be mounted on a bicycle frame, a movable member, a linkage assembly pivotally connected to and between the base and the movable member, a pivot shaft provided within and pivotally rotatable relative to the movable member, a chain guide fixed to an end of the pivot shaft, a restriction assembly provided on the pivot shaft, and a friction assembly provided within the movable member to provide a rotational friction on the restriction assembly. Whereby, the chain guide is pivotally awing toward a first direction by a force; when the chain guide swings toward a second direction which is opposite to the first direction by another force, it is forced by a swing resistance.

Abstract: The derailleur has a damper that breaks the angular movements of a chain guide. Variable volume chambers in the damper are filled with a damping fluid and connected through a controlled fluid passage system so that fluid flows between chambers in response to angular movement of the chain guide. The damper comprises a dividing body in a mobile body coaxial to the axis X, mechanically constrained so that each rotation of the dividing body about the axis X is accompanied by a translation of the dividing body along the axis X. The dividing body is mechanically constrained to the chain guide and moves with it in the angular direction about the axis X. The chambers are formed in the mobile body on opposite sides of the dividing body and change volume in opposite directions when the dividing body moves along the axis X.

Abstract: A bicycle derailleur is provided with a base member, a chain guide, a linkage assembly and a cable fixing structure. The base member is configured to be mounted to a bicycle frame. The chain guide is movable between retracted and extended positions with respect to the base member. The linkage assembly operatively couples the chain guide to the base member. The cable fixing structure is configured to fix an operation cable that moves the linkage assembly in response to an operation of the operation cable. The cable fixing structure is mounted to one of the chain guide and the linkage assembly. The cable fixing structure includes a cable attachment member to which the operation cable is fixed. The cable attachment member is movable with respect to the one of the chain guide and the linkage assembly with the operation cable being fixed to the cable attachment member.

Abstract: A bicycle stem includes a handlebar and a dual control lever which includes a brake device and a first electronic sending unit. The first electronic sending unit is detachably fixed to the brake device. The brake device and the first electronic sending unit together form an assembly space for a handlebar installed therein. The handlebar is assembled with the brake device and the first electronic sending unit in the assembly space.

Abstract: A bicycle operating device comprises a base member, an operating member, and a movable member. The movable member is configured to move an operation cable in a pulling direction to operate a bicycle component in response to a first movement of the operating member. The movable member is configured such that the operation cable is movable in a releasing direction in response to a release of the operating member from a first operated position. The movable member is configured to move the operation cable in the pulling direction to operate the bicycle component in response to a second movement of the operating member. The movable member is configured such that the operation cable is movable in the releasing direction in response to a release of the operating member from a second operated position.

Abstract: An apparatus for driving a drive chain, such as on a bicycle, may include a chainring having teeth arranged around a circumference of the chainring, and one or more magnetic portions disposed adjacent to the teeth of the chainring. The one or more magnetic portions may be disposed on the chainring and/or on a frame to which the chainring is rotatably coupled.

Abstract: An electric derailleur motor unit includes a base member, a motor, an output shaft, and a drive train. The motor is mounted to the base member. The motor has a motor shaft rotatable about a first rotational axis. The output shaft is rotatable about a second rotational axis. The drive train is operatively disposed between the motor shaft of the motor and the output shaft. The drive train includes an anti-backdriving device. The anti-backdriving device is configured to transmit rotation of the motor shaft of the motor in both rotational directions about the first rotational axis to the output shaft. The anti-backdriving device is further configured to prevent the output shaft from rotating in both rotational directions about the second rotational axis while the output shaft receives an external rotational torque from outside of the electric derailleur motor unit.

Abstract: An electronic rear derailleur comprising a fixing part, a drive element, a transmission assembly, a linkage unit, and a chain adjusting portion. The fixing part has a first joint and a fixing end. The drive element drives a drive wheel. The transmission assembly has a transmission shaft and a transmission element. The linkage unit includes a base, a revolving wheel, and a gear set. The revolving wheel is engaged with the drive portion, and the gear set is disposed in the base. The base has a first and a second end, and the chain adjusting portion has a second joint pivotally connected to the second end, so that the chain adjusting portion rotates relative to the base. The gear set is connected with the first and the second joint so as to make the first and the second joint synchronizely rotate, so that the adjusting portion shifts the chain.

Abstract: A front derailleur with controllable full rotational movement with two operator selectable radial arms—one for pole-vaulting the chain to larger sprockets, the other for sliding the chain to smaller sprockets.

Abstract: A motorised bicycle gearshift that has a deformable articulated kinematic mechanism, fixed to a bicycle frame and capable of taking up different operating configurations; a chain guide, carried by the deformable articulated kinematic mechanism, capable of taking up different positions with respect to the bicycle frame according to the different operating configurations of the deformable articulated kinematic mechanism; a motor member, comprising a motor casing and a master drive shaft that projects directly from the motor casing, the motor member being mounted on the deformable articulated kinematic mechanism so as to deform it, thus making it take up the different operating configurations. The master drive shaft is immobile in rotation and mobile in translation in the axial direction, with respect to the motor casing. This gearshift provides greater precision in use, because the possible presence of dirt on the master drive shaft does not hamper the movements thereof.

Abstract: A method for electronically controlling a bicycle gearshift comprising at least one derailleur is disclosed, comprising the sequential steps of: a) imparting a movement on the derailleur of the gearshift until the derailleur is in an intended position; b) waiting for a predetermined time period, c) performing a check whether the derailleur is in the intended position, within a possible predetermined tolerance, d) in case said check has a negative outcome, imparting a movement on the derailleur of the gearshift until the derailleur is in the intended position. A derailleur and an electronically servo-assisted bicycle gearshift comprising control electronics comprising modules adapted to carry out the method outlined above are also disclosed.

Abstract: A roller-chain tensioning assembly includes a resilient bow-shaped structure to which are mounted first, second and third guide wheels. These guide wheels are mounted in such manner that a roller chain can be threaded around said first guide wheel on side facing away from said bow, around said second guide wheel on side facing said bow, and around said third guide wheel on side facing away from said bow.

Abstract: A multiple-sprocket arrangement for mounting on a rear wheel axle of a bicycle includes a receiving body designed for mounting on the rear wheel axle, and a sprocket assembly. The sprocket assembly includes a first sprocket, the inner diameter of which is greater than an outer diameter of the receiving body and which is connected to the receiving body. The sprocket assembly further includes at least one second sprocket, the inner diameter of which is smaller than an outer diameter of the receiving body and which is designed in an unsupported manner and connected to the receiving body in a torque-transmitting manner by means of the first sprocket.

Abstract: A bicycle sprocket includes a sprocket body, and a plurality of sprocket teeth. At least one of the sprocket teeth includes a first layered member, a second layered member and a third layered member. The first layered member has a first axial surface and a second axial surface. The second layered member is attached to the first axial surface such that the first and second layered members overlap each other in an axial direction as viewed parallel to a rotational axis of the sprocket body. The third layered member is attached to the second axial surface such that the first and third layered members overlap each other in the axial direction as viewed parallel to the rotational axis of the sprocket body. The first layered member has a specific gravity that is less than those of the second layered member and the third layered member.

Abstract: A multiple sprocket assembly includes a number of sprockets attached to a hub of a bicycle frame, and a rear chain transfer device having a sliding member slidably attached to a guiding device, and a carrier attached to the sliding member and movable relative to the sprockets for engaging with a chain and for carrying and moving the chain onto the teeth of the sprockets, the rear chain transfer device includes a support attached to the bicycle frame, and the guiding device is secured to the support, the guiding device includes one or more tracks or channels for slidably engaging with and for guiding the sliding member to move relative to the guiding device.

Abstract: A front derailleur for use on devices such as bicycles is movable about a yaw axis while it moves laterally. The front derailleur may include a linkage in between a mount and a cage, with the linkage pivoting about two non-parallel axes. The front derailleur may include a linkage in between the mount and the cage that has links of different effective lengths. The front derailleur may include a single link and a cam.

Abstract: Embodiments of the present invention include bicycle chain rings for bicycles having specially shaped ramps with lifting surfaces for improved up-shifting performance. Additional embodiments of the bicycle chain rings of the present invention may be configured with one or more additional features formed within the chain rings including a transition slide, a tapered ramp face, a ramp bridge, a ramp lead, a trailing transition slide and a wear pin.

Abstract: The present invention relates to a bicycle. In particular, it relates to bicycle with torque-driven automatic transmission. The automatic transmission device mainly includes a torque sensor, a body strength selector, a slope sensor, a front gearshift driving mechanism and a rear gearshift driving mechanism.

Abstract: The invention relates to a derailleur hanger for a bicycle having an insertion aid for inserting the wheel hub between the dropouts of a fork or frame. A derailleur hanger (10) for a bicycle according to the invention having, on a first dropout (1) and/or on a second dropout (2), first and second recesses (3, 4), respectively, for receiving the corresponding ends (31, 32) of a wheel hub (30) is characterized in that the derailleur hanger (10) is configured such that the shape of a lateral surface (5) of the recess (4) is substantially steadily continued by a first guide surface (12) of the derailleur hanger (10).

Abstract: A bicycle chain guide includes a first guide plate, a second guide plate, a first connection part and a second connection part. The first guide plate has a first chain engagement surface and the second guide plate has a second chain engagement to form a chain receiving area. The first and second connection parts extend between the first and second guide plates to connect the first and second guide plates together at first and second spaced locations, respectively. The first connection part is fixed to the first guide plate by a fastener. The first guide plate has a first abutment and the first connection part has a second abutment. The first and second abutments are arranged at a rear end of the chain guide to limit relative movement of the first and second guide plates.

Abstract: There is disclosed a chain transmission comprising a driving shaft provided with one or more sprockets and a driven shaft provided with complementary sprockets, which is coupled to the driving shaft via a chain. Preferably, two chain-moving elements are provided between the driving shaft and the driven shaft, near the sprockets, by means of which a desired transmission ratio can be set via axial movement of the chain. The chain-moving elements are movable over respective gear-shifting elements upon rotation of said elements, making it possible to shift from one sprocket combination to another with a reduced risk of malfunctions. The transmission is accommodated in a closed, self-supporting casing built up of interconnected casing members, in which the shafts in question are supported.

Abstract: A sprocket assembly mounted to a hub has at least eleven sprockets. The hub is able to rotate about a rotation axis and has a plurality of spoke attachment seats and a fastening portion to a frame of the bicycle. On the hub a predetermined axial distance is defined between a plane, substantially perpendicular to the rotation axis, comprising the points of the spoke attachment seats closest to the freewheel body and a plane, substantially perpendicular to the rotation axis and defined in the fastening portion to the frame, comprising the attachment points to the frame closest to the freewheel body. All of the sprockets of the sprocket assembly, when associated with the freewheel body, have an overall axial width that is lower than or equal to the predetermined axial distance. The chain has a maximum thickness between 4.6 mm and 5.8 mm.

Abstract: A bicycle rear derailleur includes a stationary member, a base member, a linkage mechanism, a movable member, a chain guide and an inner cable fixing portion. The stationary member non-movably attached to a bicycle frame and includes an outer cable receiving portion configured to receive an outer sheath of a control cable assembly. The base member is pivotally coupled to the stationary member about an axis spaced apart from a hub axis of a rear wheel. A movable member at one end of the linkage mechanism is movable relative to the base member in response to an inner cable that is attached to a portion of the linkage mechanism. The base member can move in response to tension applied by the inner cable without moving the chain guide which is coupled to the movable member.

Abstract: A transmission device for a cycle, such as a bicycle, which includes a bottom bracket fixed relative to the remainder of the cycle frame.

Abstract: A bicycle sprocket assembly has a first sprocket with a plurality of first radially protruding portions, a second sprocket with a plurality of second radially protruding portions and a sprocket support member. The second sprocket has more teeth than the first sprocket. The sprocket support member includes a plurality of sprocket mounting portions extending radially outwardly from a freewheel engaging portion. Each of the sprocket mounting portions has first and second sprocket mounting openings for fixing the first and second sprockets, respectively. The first sprocket mounting opening is circumferentially offset from the second sprocket mounting opening with respect to a center rotational axis of the sprocket assembly. The radially innermost edge of the second radially protruding portion is spaced by a radial distance that is smaller than a radial distance of the radially outermost edge of the first sprocket mounting openings with respect to the center rotational axis.

Abstract: A synchronous drive apparatus that includes a continuous loop elongate drive structure and first and second driven rotors that are configured to cooperate with the continuous loop elongate drive structure to generate first and second opposing fluctuating corrective torques, respectively, that are configured to at least partly counteract first and second periodic fluctuating load torques, respectively.

Abstract: A front derailleur of a bicycle comprises a retaining ring disposed on a bottom end of a seat post, the retaining ring including two coupling seats symmetrically fixed thereon to axially connect with a pushing mechanism comprised of a cable rack, a limiting stem, a connecting rod set, a guiding loop, an axial pillar, an assembling bracket, and a guide plate, the coupling seat including the connecting rod set having a first, a second, a third, and a fourth connecting rods, a shaft, and the guiding loop, wherein the coupling seat includes a first hole formed on a bottom end of a side thereof so that a first screw inserts through a first bore of the cable rack and a turning spring to screw with the first hole of the coupling seat, and includes two first tabs mounted on top ends thereof respectively to connected with the axial pillar axially.

Abstract: An actuator device for a bicycle gearshift is provided. The actuator comprises an actuation mechanism, driven by a drive member and in turn to drives a derailleur of the gearshift. The mechanism comprising a member which—in the case of a knock to the mechanism—is subjected to a stress; the member is capable of elastically yielding when subjected to a stress above a predetermined stress threshold.

Abstract: A bicycle rear derailleur comprises a base member; a movable member that supports a chain guide including a pulley that rotates around a pulley axis, wherein the pulley has a pulley plane; and a linking member coupled between the base member and the movable member so that the chain guide moves laterally relative to the base member between a first lateral position and a second lateral position. The base member has a chain receiving space therein.

Abstract: A bicycle multi-gear cassette mountable to a wheel hub that generally includes a truncated conical shell and a plurality of toothed sprockets having different numbers of teeth. The shell includes a plurality of coaxial annular cylinders of variable diameter extending along an axis of the shell and a plurality of coaxial annular discs of variable diameter extending radially of the axis. The cylinders and discs are alternatingly arranged in a stepped sequence. The toothed sprockets are disposed on the shell and extend radially of the shell axis. At least one of the toothed sprockets includes a recess on a side facing an adjacent toothed sprocket having a smaller number of teeth. The recess includes a first region having a first depth and a second region having a second depth. The first depth is greater than the second depth. The shell and the plurality of toothed sprockets embody a single piece.

Abstract: A bicycle derailleur comprises a base member; a movable member that supports a chain guide, wherein the movable member is coupled to the base member so that the movable member moves relative to the base member for moving a chain among a plurality of sprockets; an intermediate member that mounts the base member to a bicycle frame; a first adjusting mechanism that adjustably sets a position of the intermediate member relative to the bicycle frame; and a second adjusting mechanism that adjustably sets a position of the base member relative to the intermediate member.

Abstract: A bicycle sprocket apparatus comprises a sprocket mounting member, a first sprocket, and a second sprocket. The sprocket mounting member includes a hub mounting portion and a sprocket mounting portion, wherein the hub mounting portion is structured to be mounted to a rotating hub that rotates around a rotational axis. The sprocket mounting portion includes a first sprocket mounting surface that faces in a first direction and a second sprocket mounting surface that faces in an opposite second direction. The first sprocket is disposed at the first sprocket mounting surface, and the second sprocket is disposed at the second sprocket mounting surface. A fastener fastens the first sprocket to the first sprocket mounting surface, and a chain supporting structure extends from the fastener in the first direction and projects in the first direction away from a side surface of the first sprocket that faces in the first direction.

Abstract: A bicycle derailleur includes a mounting member, at least one linkage member, a movable chain guide and a chain guide tensioning mechanism. The mounting member is configured to be attached to a bicycle frame. The linkage member is supported to the mounting member. The movable member is movably coupled to the mounting member via the linkage member. The chain guide is pivotally connected to the movable member to pivot about a pivot axis that extends through the movable member. The chain guide also supports a guide pulley and a tension pulley. The chain guide tensioning mechanism is supported to the movable member at a point spaced apart from the pivot axis configured to bias the chain guide in a direction about the pivot axis.

Abstract: A transmission neutralizing structure for a pedal-powered vehicle is disclosed. The transmission neutralizing structure is provided on one of sprocket sets of the vehicle, and includes a free gear and a bearing by which a center of the free gear is coupled with a rotatory assembly so that the rotatory assembly and the free gear are rotationally disconnected in both directions. The pedal-powered vehicle has a chain shiftable between the sprocket set and the free gear under control of a derailleur gear unit. When the derailleur gear unit is set in a neutral gear position, the chain is engaged with the free gear. The free gear further has a safety device, which kinetically couples the free gear with the sprocket set.

Abstract: The chain guide of a bicycle rear derailleur is a chain guide which is connected to a movable member so that this guide is free to swing about a center pivot axis. The chain guide has a pair of plate members rotatably supporting a guide pulley and a tension pulley. One of the plate members is provided with a chain slip prevention part which is disposed between both plate members in the vicinity of the guide pulley. Preferably, the chain slip prevention part has a width of ten mm or greater and fifty mm or less.

Abstract: An electrical bicycle shift control assembly is provided that includes at least one electrical bicycle shift control device. The shift control device includes a handlebar mounting portion configured to be clamped onto a handlebar and an electrical shift control switch portion. The electrical switch portion has an operating member arranged to move relative to the handlebar mounting portion between a neutral position and an actuating position. Preferably, the electrical switch portion is detachably coupled to the handlebar mounting portion via a mating mounting structure to be removable from the handlebar mounting portion without removing the handlebar mounting portion from the handlebar. Preferably, a bicycle computer unit including a display screen is supported by the handlebar mounting portion. The operating member can include a dial-shaped element or a lever-shaped element that is configured to rotate about an operating axis.

Abstract: A front derailleur basically comprises a base member, a chain guide, inner and outer links, a first arm portion, and a coil spring. The chain guide is freely swingably coupled to the base member to guide a chain in a direction of shifting gears. Each of the outer link and the inner link has first and second sections freely rotatably coupled to the base member and the chain guide, respectively. The outer link and the inner link are disposed substantially parallel to each other. The first arm portion extends in a direction away from the base member. The coil spring has first and second ends connected to the base member and a free end of the first arm portion such that a biasing force is applied on the chain guide in a direction toward a frame of the bicycle when the base member is installed on the frame.

Abstract: A transmission device for a cycle, such as a bicycle, which includes a bottom bracket fixed relative to the remainder of the cycle frame.

Abstract: To achieve downsizing and weight reduction of a derailleur shaft and the mounting structure thereof and to improve the rigidity of the derailleur shaft without increasing the thickness thereof more than necessary. A transmission case is divided into left and right halves, and the left and right halves are provided with bosses therein having holes opposing each other. The bosses are brought into abutment with each other and united by fitting tightening bolts to the holes of the bosses and tightening the same. A sleeve-shaped derailleur shaft is fitted on the outer periphery of the bosses to support and mount the derailleur shaft. The derailleur shaft includes a hole at the shaft end thereof. A mounting position of the derailleur shaft is achieved by a pin inserted into the hole and a hole provided on one of the cases.

Abstract: The invention relates to a derailleur hanger for a bicycle having an insertion aid for inserting the wheel hub between the dropouts of a fork or frame. A derailleur hanger (10) for a bicycle according to the invention having, on a first dropout (1) and/or on a second dropout (2), first and second recesses (3, 4), respectively, for receiving the corresponding ends (31, 32) of a wheel hub (30) is characterized in that the derailleur hanger (10) is configured such that the shape of a lateral surface (5) of the recess (4) is substantially steadily continued by a first guide surface (12) of the derailleur hanger (10).

Abstract: A top/bottom pull front derailleur includes a base member, inner and outer links, a chain guide and a top/low adjustment mechanism coupled to the base member. The links are pivotally coupled between the base member and the chain guide. The inner link has a wire fixing part that can be used in top and bottom pull arrangements. The chain guide is configured to move between a retracted position and an extended position relative to the base member. The adjustment mechanism includes top and low adjusting bolts with longitudinal bolt axes angled more than zero degrees relative to a plane of the bicycle frame. The adjustment mechanism is mounted rearwardly of single attachment portion of the outer link or between a pair of attachment portions of the outer link. The bolt axes are preferably angled about 45 degrees or about 90 degrees relative to the plane of the frame.

Abstract: A bicycle front derailleur includes a chain guide that is provided with a pushing element that is movable relative to the chain guide to assist in shifting a bicycle chain from a smaller front sprocket to an adjacent larger sprocket. The chain guide is part of a movable member that is movably coupled to a base member via a linkage assembly. The pushing element is rotatably coupled to the chain guide portion and activated by a chain to move relative to the inner chain guide member from a first position with the pushing element at rest to a second position in response to activation by the chain. The contact surface moves laterally outwardly into the chain receiving slot toward the outer chain guide member as the pushing element moves from the first position to the second position.

Abstract: A shift control apparatus is provided for a bicycle having a plurality of front sprockets and a plurality of rear sprockets, wherein a front derailleur shifts a chain among the plurality of front sprockets and a rear derailleur shifts the chain among the plurality of rear sprockets. The apparatus comprises a shift unit that provides signals for shifting the front derailleur and the rear derailleur; and a prohibiting unit operatively coupled to the shift unit and providing signals so that the chain is prohibited from engaging at least one of i) a laterally innermost front sprocket in combination with a laterally outermost rear sprocket, and ii) a laterally outermost front sprocket in combination with a laterally innermost rear sprocket.