A bicycle rear derailleur includes a base member, a movable member, a linkage assembly and an axial spacing adjustment structure. The base member includes a mounting axle configured to be attached to a bicycle frame. The movable member includes a chain guide. The linkage assembly is coupled between the base member and the movable member to move the chain guide between a retracted position and an extended position. The axial spacing adjustment structure is disposed on the mounting axle between the base member and the frame. The axial spacing adjustment structure includes a removeable first spacer and a second spacer, the first spacer having a first axial side facing the frame and a second axial side configured and arranged to engage the second spacer.