| 摘要 |
<p>The bicycle has the rear wheel driven directly off a crank via a hub gear, and without any chain connection. The hub has an epicyclic reduction gear with one or several ratios and is braced on the frame by bearings (AR). The drive gear is suitable for folding and requires no chain guards etc. It prevents clothes being soiled by the chain and reduces the weight. The hub pedals and wheel are removed in one piece for storage in a compact space.</p> |
