| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce time and labor required for position adjustment to step on a pedal in starting.SOLUTION: A pair of fixed magnets 5a and 5b disposed around a crankshaft 21 are fixed to a bicycle frame F. When a pedal is at a stepping position, a pair outer magnets 7a and 7b facing each of the fixed magnets 5a and 5b are mounted in the crankshaft 21. In the fixed magnets 5a and 5b and the outer magnets 7a and 7b, planes face each other at different poles. The outer magnets 7a and 7b are attracted to the close-by fixed magnets 5a and 5b, thereby rotating the crankshaft 21 together with the attraction. Therefore, when starting a bicycle, a left crank 11a is always disposed at the stepping position so as to reduce time and labor required for position adjustment of the pedal.</p> |
