| 摘要 |
A rear bicycle derailleur is provided which includes (1) a chain guide formed of a guide pulley, a tension pulley and first and second plates supporting the guide and tension pulleys, and (2) a derailleur body having a movable member supporting the chain guide and support means supporting the movable member to be movable axially of the multistage sprocket assembly. The first plate includes a first restrainer at a side of the first plate adjacent the derailleur body, with the first restrainer being positioned radially outwardly relative to the guide pulley at a location outside a first predetermined chain movement path along which the chain travels from a high speed sprocket of the multistage sprocket assembly to the tension pulley through the guide pulley when the multistage sprocket assembly rotates in reverse. The first restrainer prevents the chain from moving away from the first chain movement path when the multistage sprocket assembly rotates in reverse. The second plate includes a second restrainer positioned radially outwardly relative to the guide pulley at a location outside a second predetermined chain movement path along which the chain travels from a low speed sprocket of the multistage sprocket assembly to the tension pulley through the guide pulley when the multistage sprocket assembly rotates in reverse. The second restrainer prevents the chain from moving away from the second chain movement path when the multistage sprocket assembly rotates in reverse. |
