Sprocket assembly for derailleur change speed gear - incorporates hub which can slide axially on wheel hub

摘要

The bicycle has a derailleur-type change speed gear. It has three sprockets (1,2,3) attached to its rear wheel. The three sprockets are formed integrally with a common hub (4). The hub has a splined bore which fits over the matching splines (5) of the wheel hub. The sprocket assembly can drive the rear wheel but has a limited deg. of axial movement. This axial movement enables the sprocket which is being driven by the chain to align itself with the chain wheel. This feature reduces friction between the chain and chain wheel and sprocket, and improves the mechanical efficiency of the bicycle. USE - Bicycles with derailleurs-type change speed gear.