Brake drum for use in screw-locking device of wheel of motor bicycle, has annular post comprising external annular wall that is connected to circular flange, and annular heat sink positioned between inner and external annular walls

摘要

The drum (15) has an annular post (31) axially extending from an external edge from a circular flange. The annular post comprises an inner annular wall for receiving braking forces that are applied by braking jaws (23). An external annular wall (33) is connected to the circular flange. An annular heat sink is positioned between the inner and external annular walls. The inner wall comprises an end close to the circular flange and another end that is away from the circular flange. The circular flange and the external wall are made from a steel sheet having thickness of about 1-2 mm. An independent claim is also included for a screw-locking device.