Team Associated B4 Bearing Kit. Product Information. This is a bearing kit by Avid RC for almost every version of the RC10 after the B2 line. The bearings haven't changed through out their revisions. This is not the bearing kit for the B4.2 or B4.1. The B4.1 went to 10x16x4 diff bearings from the 3/8 x 5/8".