A derailleur hanger alignment pre-checking device, for use on a bicycle having a cassette comprising multiple sprockets and a rear derailleur having a derailleur cage, includes an elongated body having a longitudinal axis and an elongated planar surface disposed substantially parallel to the longitudinal axis, and including a handle portion and a hanger portion. The hanger portion includes a slot cavity having an arcuate rear wall, the slot cavity being configured to receive a portion of a sprocket of the cassette. The slot cavity and planar surface are configured so that when a sprocket is received in the slot cavity the planar surface will be positioned facing a planar surface of the derailleur cage.

A bicycle gearshift mechanism has a base element, a pivot mechanism, a movable element, and a chain guide arrangement. The pivot mechanism connects the base element to the movable element. The chain guide arrangement is connected, rotatably about a rotary axle, to the movable element. The base element comprises a first attachment end, which is coaxial with respect to the rear-wheel axle or axis, and a second attachment end for coupling to the pivot mechanism

A bicycle gearshift mechanism has a base element, a pivot mechanism, a movable element, and a chain guide arrangement. The pivot mechanism connects the base element to the movable element. The chain guide arrangement is connected, rotatably about a rotary axle, to the movable element. The base element comprises a first attachment end, which is coaxial with respect to the rear-wheel axle or axis, and a second attachment end for coupling to the pivot mechanism

A rear derailleur of a bicycle includes a fixing portion connected to a frame of the bicycle, a linkage assembly pivotally connected to the fixing portion, a moving portion pivotally connected to the linkage assembly, a chain guide assembly connected to the moving portion, a driving assembly, a rechargeable battery for providing an electrical energy required for the motor, a coil, and a wireless charging circuit for receiving an electric power of the coil for charging the rechargeable battery. The driving assembly includes a motor including and a driving gear assembly connected to the linkage assembly. The motor includes an output shaft for driving the driving gear assembly and for driving the linkage assembly to pivot via the driving gear assembly, thereby to drive the moving portion and the chain guide assembly to move. The coil receives an external charging power and is disposed on the fixing portion, the moving portion, or the linkage assembly.

A rear derailleur of a bicycle includes a fixing portion connected to a frame of the bicycle, a linkage assembly pivotally connected to the fixing portion, a moving portion pivotally connected to the linkage assembly, a chain guide assembly connected to the moving portion, a driving assembly, a rechargeable battery for providing an electrical energy required for the motor, a coil, and a wireless charging circuit for receiving an electric power of the coil for charging the rechargeable battery. The driving assembly includes a motor including and a driving gear assembly connected to the linkage assembly. The motor includes an output shaft for driving the driving gear assembly and for driving the linkage assembly to pivot via the driving gear assembly, thereby to drive the moving portion and the chain guide assembly to move. The coil receives an external charging power and is disposed on the fixing portion, the moving portion, or the linkage assembly.

A bicycle rear derailleur has a base member mountable to a bicycle frame, a movable member movably coupled to the base member, a chain guide assembly rotatably connected to the movable member for rotation about a rotational axis, a biasing element configured and arranged to bias the chain guide assembly for rotation in a first rotational direction with respect to the movable member, and a fluid damper having a fluid cavity containing a volume of fluid. The fluid damper is operatively disposed between the chain guide assembly and the movable member to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction opposite to the first rotational direction. The fluid damper has a guide wheel configured to route a chain and rotatable about the rotational axis.

A bicycle rear derailleur has a base member mountable to a bicycle frame, a movable member movably coupled to the base member, a chain guide assembly rotatably connected to the movable member for rotation about a rotational axis, a biasing element configured and arranged to bias the chain guide assembly for rotation in a first rotational direction with respect to the movable member, and a fluid damper having a fluid cavity containing a volume of fluid. The fluid damper is operatively disposed between the chain guide assembly and the movable member to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction opposite to the first rotational direction. The fluid damper has a guide wheel configured to route a chain and rotatable about the rotational axis.

A bicycle derailleur comprises a circuit board, an electrical user interface, a motor housing, and a motor unit. The electrical user interface includes a user accessing portion configured to receive a user input. The motor housing includes a motor accommodating space. The motor unit is provided in the motor accommodating space and configured to generate rotational force and configured to be electrically connected to the circuit board. A first direction is defined from the circuit board toward the electrical user interface or from the electrical user interface toward the circuit board. The plurality of second directions is defined to be perpendicular to the first direction. The motor unit is at least partly provided between the user accessing portion of the electrical user interface and the circuit board when viewed in at least one of the plurality of second directions.

A bicycle rear derailleur includes a movable member and a chain guide assembly rotatably connected to the movable member. The bicycle rear derailleur also includes a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface, a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member, and a damper device disposed between the chain guide assembly and the movable member. The damper device is operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member. The damper device includes a friction device that is radially inner relative to the biasing device. The friction device includes a friction member having at least one friction surface biased against and in frictional engagement with the pivot member.

A bicycle rear derailleur includes a movable member and a chain guide assembly rotatably connected to the movable member. The bicycle rear derailleur also includes a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface, a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member, and a damper device disposed between the chain guide assembly and the movable member. The damper device is operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member. The damper device includes a friction device that is radially inner relative to the biasing device. The friction device includes a friction member having at least one friction surface biased against and in frictional engagement with the pivot member.