Apparatus for reducing the mass and the responsive inertia of a bearing cartridge for a disc drive actuator assembly, the bearing cartridge including a stationary shaft, a bearing assembly and a bearing sleeve. The bearing assembly is disposed between, and rigidly attached to, the stationary shaft and the bearing sleeve, to facilitate radial movement of the bearing sleeve relative to the stationary shaft. The disc drive actuator assembly has an actuator rigidly attached to, and supported by, the bearing cartridge. The bearing assembly has an inner race rigidly attached to the stationary shaft, and an outer race rollingly engaging a plurality of roller bearings disposed between the inner and outer races. The outer race has a chamfered edge in a plane between a reference vertical axis and a reference horizontal axis, and the bearing sleeve has an internal taper matingly joining the chamfered edge to provide a miter joint therebetween.