| 摘要 |
<p>A pedal drive system for a bicycle includes a front spiral cone pulley and a rear pulley. The front spiral cone pulley is attached to a crank arm, and the rear pulley is attached to a rear wheel on a bicycle in some embodiments. A power cable, or tension linkage, extends between the front spiral cone pulley and the rear pulley. The front spiral cone pulley is angularly moveable relative to the first crank arm such that the radial position of the point of engagement between the power cable and the front spiral cone pulley may be selectively manipulated for controlling the gear ratio between the front spiral cone pulley and the rear pulley. In some embodiments, the rear pulley is also a spiral cone pulley.</p> |
