| 摘要 |
<p>An improved bicycle pedal crank assembly that allows a longer lever arm between the foot pedal and the crank assembly bottom bracket centre line during the power stroke; on the return stroke the lever arm distance is shortened. A linear bearing or similar device is mounted onto the end of the bottom bracket assembly, the crank itself reciprocating in and out of said bearing. Cams that optimize the pedal motion are located at both ends of the bottom bracket housing.</p> |
