Sprocket for use as hub for rear wheel of bicycle, has hub casing rotatably supported at hub spindle, and driving force measuring part comprising sensor for measuring space between two facing parts and/or displacement of space

摘要

The sprocket (10) has a drive part (22) rotatably supported at a hub spindle (20) and receiving a driving force input element i.e. toothed ring-pack (80). A hub casing (24) is rotatably supported at the hub spindle and operatively coupled with the drive part for rotating the spindle. A facing part is coupled with the drive part. Another facing part is coupled with the spindle and attached with the former facing part with a space between the two parts. A driving force measuring part (26) comprises a sensor to measure the space between the facing parts and/or adjustment of the space. The sensor is selected a group consisting of an optical type sensor, an eddy current type sensor and an electrostatic capacitance type sensor i.e. capacitor sensor.