Bicycle sprocket and crank - has two adjustable toothed plates on crank to reduce diameter at TDC

摘要

The bicycle sprocket and crank assembly has two curved toothed plates (7, 8). These are diametrically opposed and the spacing is adjustable on a support (6). The adjustment is by parallel slots (71, 72) to house locking bolts (11) on the plates and supports. The supports are radial arms and there are guide cheeks for the chain. There is a guide cheek at at least one end of the toothed parts. Each cheek joins two ends relative to the two parts. The cheeks also have parallel slots. Pedal cranks (3) are provided.