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.

An electromechanical control system for a bicycle has a switch device, the switch device operating a switch between at least three positions. A control communication device transmits signals responsive to operation of the switch. The electromechanical control system includes an operation device configured to respond to signals transmitted by the control communication device. Signals transmitted by the control communication device include commands to listen and commands to operate.

An electromechanical control system for a bicycle has a switch device, the switch device operating a switch between at least three positions. A control communication device transmits signals responsive to operation of the switch. The electromechanical control system includes an operation device configured to respond to signals transmitted by the control communication device. Signals transmitted by the control communication device include commands to listen and commands to operate.

A bicycle sprocket includes a first sprocket body and a plurality of first sprocket teeth. The first sprocket teeth include a plurality of tooth tip portions and a plurality of tooth bottom portions. The tooth bottom portions include at least one first tooth bottom portion and at least one second tooth bottom portion. The at least one first tooth bottom portion has a first tooth bottom shape. The at least one second tooth bottom portion has a second tooth bottom shape. The first tooth bottom shape is different from the second tooth bottom shape.

A bicycle sprocket includes a first sprocket body and a plurality of first sprocket teeth. The first sprocket teeth include a plurality of tooth tip portions and a plurality of tooth bottom portions. The tooth bottom portions include at least one first tooth bottom portion and at least one second tooth bottom portion. The at least one first tooth bottom portion has a first tooth bottom shape. The at least one second tooth bottom portion has a second tooth bottom shape. The first tooth bottom shape is different from the second tooth bottom shape.

A shifting system for a human-powered vehicle comprises a controller. The controller is configured to receive a driving torque and a cadence of the human-powered vehicle from at least one sensor. The controller is configured to determine a permitted shift timing based on the driving torque and the cadence. The controller is further configured to control a shift mechanism to perform a gear shift during the permitted shift timing in accordance with a permitted cadence range and a first threshold of the driving torque.

A shifting system for a human-powered vehicle comprises a controller. The controller is configured to receive a driving torque and a cadence of the human-powered vehicle from at least one sensor. The controller is configured to determine a permitted shift timing based on the driving torque and the cadence. The controller is further configured to control a shift mechanism to perform a gear shift during the permitted shift timing in accordance with a permitted cadence range and a first threshold of the driving torque.

A bicycle derailleur includes a base member mountable to a bicycle frame and having first and second laterally spaced mounting portions defining first and second planes, and a space therebetween dimensioned to receive a portion of the bicycle frame. A first mounting arrangement defines a first pivot axis oriented at an acute angle relative to the first and second planes. A second mounting arrangement defines a second pivot axis parallel to the first pivot axis. A first link is pivotally connected to the first mounting arrangement and a second link is pivotally connected to the second mounting arrangement. A moveable member is pivotally connected to the first and second links. A battery may be mounted on the base member and electrically connected with a motor carried by the moveable member.

A bicycle derailleur includes a base member mountable to a bicycle frame and having first and second laterally spaced mounting portions defining first and second planes, and a space therebetween dimensioned to receive a portion of the bicycle frame. A first mounting arrangement defines a first pivot axis oriented at an acute angle relative to the first and second planes. A second mounting arrangement defines a second pivot axis parallel to the first pivot axis. A first link is pivotally connected to the first mounting arrangement and a second link is pivotally connected to the second mounting arrangement. A moveable member is pivotally connected to the first and second links. A battery may be mounted on the base member and electrically connected with a motor carried by the moveable member.

A clutch unit of a bicycle derailleur includes a main body, a cover for the main body, a positioning assembly, and a pressure-applying assembly. Both assemblies are received in a space between the main body and the cover. The main body has a top side with a receiving groove and is pivotally connected with a rotating shaft, which extends out of a bottom portion of the receiving groove. The positioning assembly includes a ratchet, a pawl, and an elastic member. The ratchet is pivotally connected in the receiving groove, can rotate with the rotating shaft, and has ratchet teeth annularly arranged at an equal spacing. The pawl is adjacent to and can move toward and away from the ratchet, has a meshing tooth for meshing with the corresponding ratchet tooth, and is elastically biased toward the ratchet by the elastic member. The pressure-applying assembly applies resistance to the ratchet.