Patent ID: 7988574

Claim:
A transmission for a bicycle comprising: a derailleur shaft rotatably supported by a case member provided on a vehicle body frame, the derailleur shaft having a longitudinal axis and formed with a guide hole; a derailleur arm rotatable about the derailleur shaft; a guide rotational body which is rotatably supported by the derailleur arm and around which an endless power transmission belt is wound, the guide rotational body having an axis of rotation, the axis of rotation being parallel to the derailleur shaft longitudinal axis; and an operating pin connected to a wire which moves in a fore-and-aft direction in accordance with a speed-change operation, the operating pin fitted to a proximal portion of the derailleur arm, and rotated by being guided through the guide hole of the derailleur shaft, so that the derailleur arm is rotated with respect to the derailleur shaft and moved toward a center axis of the derailleur shaft by the operating pin being moved while being guided through the guide hole by the speed-change operation via the wire.