A taper bore bearing assembly permits variability in diameter of the rotating shaft. An annular cylinder is mechanically coupled to the rotatable shaft and a bearing element is in turn mechanically coupled to the annular cylinder, which includes a tapered bore so that an interior diameter of the annular cylinder decreases from one end to the other. An inner race of the bearing element includes accepts the annular cylinder. The interior diameter of the inner race decreases from one end to the other. A locking ring locks the annular cylinder to the bearing element. Holes extend radially through the locking ring. A screw thread mechanically couples with the bearing assembly, which screw thread is inscribed on an interior surface of the locking ring. Cutout sections in the screw thread are formed by the holes. Setscrews disposed in the holes hold the locking ring in place. The setscrews include a foot to mechanically couple with the bearing assembly, which foot includes a portion of a screw thread that matches one of the cutout sections or holes of the screw thread.