Wheel rim assembly (10) is formed in three parts, the cylindrical rim base (20), inner side flange (22) and reinforcing rim (34) all as one part, and the combination bead seat (50), annular outer side flange (52) and reinforcing rim (60) as a second part, and lock ring (76) as the third part. The flanges (22, 52) are unitarily connected to their respective rim base (20) and bead seat (50), both having reinforcing rims (34, 60), respectively, which are located in axial alignment with the cylindrical surfaces of the rim base and bead seat, respectively, lending additional strength to the flanges (22, 52). The sloped lock ring engagement surface (64) of the reinforcing rim 52 opposes a similarly sloped bearing surface (76) of the lock ring (72). The structures are fabricated by a forging process which, though expensive, significantly increases the strength of the structure.