主权项 |
1. A derailleur for a bicycle, the derailleur comprising:
a fixed B knuckle pivot portion; a rigid case portion pivotably mounted to the B knuckle pivot portion and housing an electric motor; a movable P knuckle pivotably connected to the case portion at a position spaced from the B knuckle pivot portion; a belt fixedly attached to a shaft of the B knuckle and looping around a shaft of the P knuckle; and a bicycle chain tensioner supported by the P knuckle; wherein the electric motor is operatively connected to the B knuckle pivot portion by a gear assembly, such that operation of the electric motor causes the case portion to pivot around the B knuckle; and wherein an orientation of the P knuckle is maintained by the belt as the case portion pivots around the B knuckle. |