Crank drive for bicycle - has uneven transmission between crank and rear wheel, with transmission minimum set to vertical pedal position.

摘要

The drive has a drive member e.g. a crank, and a driven member, e.g. a rear wheel. There is at least one unfavourable drive position with low power transmission, in the power flux between the two elements. A transmission with uneven transmitting characteristics is located between crank and wheel. The crank drive has a rear sprocket wheel (1), fastened to a drive disc (2), which is fastened eccentrically turnable with a pinion offset (e) on the wheel axle (3). The drive disc is connected to the driven disc (8) on the wheel hub (9), via a hinge joint (6,7). This is at a distance to the wheel axle, resp. rotary axis. ADVANTAGE - Overcomes unfavourable drive positions (esp. vertical pedal position).