| 摘要 |
<p>A rear derailleur (100) for a bicycle having a bracket (5) connected to a bicycle frame (12), a guide wheel (1) for shifting a chain, a support member (4) for supporting the guide wheel (1), a base member (6) pivotably attached to the bracket (5), a tension spring (10) for biasing the base member (6) in a predetermined pivoting direction, and a parallelogram link mechanism (7,8) for linking the support member (4) and the base member (6). The bracket (5) has a mounting section (5B) formed in a region thereof adjacent the bicycle frame (12) and opposed to the bicycle frame (12). The tension spring (10) is attached to the mounting section (5B) so as to lie between the bicycle frame (12) and the mounting section (5B). The tension spring (10) is a coil spring having one end thereof fixed to the mounting section (5B), and the other end fixed to the base member (6). An axis extends through a middle tubular space of the coil spring (10) for pivotally connecting the base member (6) to the bracket (5). The link mechanism (7,8) includes an inner pivotal link (8), and an outer pivotal (7) link disposed farther from the bicycle frame (12) than the inner pivotal link (8) is. The inner pivotal link (8) is connected at one end thereof to the base member (6) by a first pivot pin (19A). The first pivot pin (19A) is disposed closer to the bicycle frame (12) than the mounting section (5B) is. <IMAGE></p> |
