Bicycle hub

A bicycle hub is provided with a hub axle 40, a hub shell 32 and a pair of bearing units. Each of the bearing units has an inner race 61, 71 supported on one axle end of the hub axle, an outer race 62, 72 threadedly coupled to an inner tubular surface of the hub shell 32, and a plurality of first rolling members 60, 70 disposed between the inner and outer races 61, 71; 62, 72. Preferably, a first stopper ring 63, 73 is coupled to one of the first inner and outer races 61, 71; 62, 72 to form an axial abutment that is arranged to contact the other of the first inner and outer races 61, 71; 62, 72 to prevent axial separation of the first inner and outer races 61, 71; 62, 72 prior to installation of the bearing unit between the hub axle 40 and the hub shell 32.