A MULTI-STAGE GEAR CRANK FOR A CYCLE

摘要

A multi-stage gear crank for a bicycle has chain detaching means facilitating disengagement of a driving chain from the teeth of sprockets, the detaching means being provided at teeth positioned in the vicinity of the upper and lower dead points of a larger diameter sprocket corresponding to the crank arms respectively, whereby the chain is adapted to be switched to a smaller diameter sprocket from the larger diameter sprocket at the upper dead point thereof.