A bicycle wheel or pedal crank hub with a bearing preload device in which an axle end cap that is attached to the end of an axle extending through the hub and supported on a bearing assembly is used for preloading the hub bearing assembly together with a split compression ring. For adjusting the preload on the hub bearing assembly, the compression ring is expanded or contracted causing a beveled surface of the compression ring to act on a bevel of either an annular circumferential flange of the axle end cap or a spacer disposed between the compression ring and the circumferential flange of the axle end cap.