Abstract: There is disclosed a bearing for mounting on a multi-sided shaft having an outer race and an inner race coaxial with and rotatable relative to the outer race. The inner race is formed with a central bore having a plurality of internal corners which accommodate a multi-sided shaft. The central bore is preferably adapted to accommodate hexagonal and square shafts. The central bore has at least one circumferential groove in the bore and an elastomeric ring mounted into the groove. The grooves are formed at such depth that the elastomeric ring is exposed at the internal corners of the central bore whereby when the bearing is mounted the elastomeric material will contact the shaft and dampen the relative motion between the bearing and the shaft.