An assisting apparatus for using power from a rotating member to assist the operation of a bicycle transmission includes a mounting unit; an input transmission member coupled to the mounting unit, wherein the input transmission member moves to at least a neutral position, to an upshift position and to a downshift position; and an output transmission member coupled to the mounting unit, wherein the output transmission member moves to at least a first output position and a second output position. A rotating member engaging member moves between a rotating member engaging position and a rotating member disengaging position, and a motion transmitting mechanism transmits motion from the rotating member engaging member to the output transmission member. A switching mechanism moves the rotating member engaging member to the rotating member engaging position when the input transmission member is in at least one of the upshift position and the downshift position.