| 摘要 |
PROBLEM TO BE SOLVED: To easily install a transmission of relay type free from any interference with legs by employing a versatile change-gear hub. SOLUTION: In a cantilever drive unit of a bicycle in which a rear frame 2 having a drive system to a front frame 1 is pivotably supported in an oscillating manner, a change-gear hub 9 is installed between a crankshaft 4 (a crank sprocket 6) and a rear wheel hub (to be connected to a free wheel sprocket 12), and the crankshaft 4 and the change-gear hub 9, and the change- gear hub 9 and the rear wheel hub (the free wheel sprocket 12) are connected to each other through power transmission members 7, 11, respectively. The cantilever drive unit is provided with a rear frame 2 having the drive system which is easy in attachment/detachment to/from the front frame 1 during the assembly, etc., and also easy in maintenance and inspection through disassembly. A bicycle with a built-in change-gear can be provided at a low cost only by fitting the versatile change-gear hub 9 on the market on an intermediate part of the rear frame 2 without changing any part of the crank sprocket part or the rear wheel hub part.
|
