| 摘要 |
<p>A bicycle belt drive system is provided which employs a toothed endless power transmission belt made primarily of polymeric material. The teeth of such belt are employed during starting of the bicycle to provide a mare positive interconnection between driving and driven pulleys of the drive system. At least one of the pulleys has means for changing the mechanical advantage between the driving pulley and the driven pulley in response to rotational speed changes in the one pulley and thus in the bicycle speed. The is bicycle drive system operates automatically without the attention of the bicycle operator.</p> |
