BICYCLE DERAILLEUR

A bicycle derailleur comprises a derailleur body, a charging port, a charging-port cover, and a cover connector. The charging port is configured to be detachably connected to a charging cable to charge an electric power source. The charging-port cover is configured to be detachably attached to the charging port. The charging-port cover has a detachment state in which the charging-port cover is detached from the derailleur body to allow connection between the charging port and the charging cable. The cover connector is configured to couple the charging-port cover to the derailleur body in the detachment state.