| 摘要 |
<p>In a first aspect of the invention the chain casing for a bicycle comprises at the crankshaft (6) an opening (7) having a diameter which is considerably greater than the diameter of the crankshaft. The edge of the opening sealingly cooperates with a disc-like element formed on the crankshaft, for example by means of a sealing means (10), which is connected to the chain casing and slides along the disc-like element. According to a second aspect of the invention the chain casing comprises an opening (15) accommodating the hub (13) of the rear wheel (14) with a diameter which is greater than the diameter of the hub. Between the edge of the opening and the hub a disc-like sealing element (16) is positioned, for example made of rubber. Preferably, this sealing element is releasably attached to the chain casing and slides along the hub to obtain a proper seal.</p> |
