Friction ring for a synchronization unit of a gear changing transmission. The friction ring, when in an uninstalled state, is circumferentially pre-loaded and includes an annular front side, an annular rear side, a conical inner friction surface, a conical outer installation surface, and a first separation surface facing and in contact with a second separation surface and defining a circumferential separation area in the friction ring. The friction ring is prevented from contracting radially and circumferentially by said contact and is capable of expanding radially and circumferentially while being circumferentially pre-loaded.