An improved knife sharpener may include a hub body, a freewheel unit, a connecting sleeve and an external freewheel. The connecting sleeve connects to the ratchet sleeve of the hub body in order to provide more space for the external freewheel. With the design of the connecting sleeve and the external freewheel unit, the hub body loaded with more smaller freewheels provides more pedaling speeds for a bicycle travelling downhill. When cycling downhill by using the smaller diameters of the sprockets, the smaller sprockets of the external freewheel can help a cyclist to maintain an optimum pedaling speed in a slopy terrain, and the speed of the bicycle can be easily controlled.
BICYCLE HUB AND FLYWHEEL STRUCTURE
2017-01-26
Patent
Elektronische Ressource
Englisch