| 摘要 |
The present invention provides a transmission casing for a bicycle whic h has the sufficient strength and rigidity and has the simple structure while capable of hermetically sealing a transmission body of the bicycle. In a transmission casing for a bicycle in which a transmission body of a bicycle is covered with a casing and a plurality of transmission shafts are supported by the casing, the transmission casing is constituted of a light-metal-made reinforcing member made of aluminum, a light alloy or the like which supports shaft portions of the plurality of transmission shafts, and a fiber - reinforced-plastic-made cover member which is integrally laminated to an inner surface of the light-metal-made reinforcing member so as to hermetically seal the transmission body, the light-metal-made reinforcing member has a strength necessary for supporting the plurality of transmission shafts, and the fiber-reinforced-plastic-made cover member has a residual rigidity by subtracting rigidity obtained by the metal-made- reinforcing member from rigidity necessary for preventing the deformation of the whole casing. |
