Variable length bicycle crank - has sliding sections under control of guide chains and maintained at equal lengths

摘要

The pedal cranks (5) can have their length varied by sliding via two flexible connections (7,8) fixed to the crank ends (5,5A) and passing along their length. They cross inside the hollow shaft (4). The crank and shaft are held perpendicular in two blocks (1,1A). One of the has fixing lugs (3) for an exterior sprocket. The flexible connections are chains and their equal tension ensures equal length of the cranks. Shortened cranks enable pedal power to be used when riding around sharp curves with the bicycle inclined accordingly.