REAR DERAILEUR OF BICYCLE

A rear derailleur of a bicycle includes a fixing portion connected to a frame of the bicycle, a linkage assembly, a moving portion, a chain guide assembly, and a driving assembly. The linkage assembly is pivotally connected to the fixing portion. The moving portion is pivotally connected to the linkage assembly. The chain guide assembly is connected to the moving portion. The driving assembly includes a motor and a driving gear assembly connected to the linkage assembly. The motor includes an output shaft for driving the driving gear assembly. The output shaft of the motor drives the linkage assembly to pivot via the driving gear assembly, thereby to drive the moving portion and the chain guide assembly to move. A pivot shaft and a detachable battery module are disposed on the moving portion. The chain guide assembly is pivotally connected to the pivot shaft. The battery module provides an electric power to the motor.