The present invention provides a bicycle rim assembly adapted to be coupled to a hub to create a bicycle wheel. The rim assembly includes a rim and a cover coupled to the rim. The rim defines a central plane and comprises an annular inner wall and an annular outer wall cooperating with the inner wall to define a cavity. The rim further includes annular projections spaced laterally relative to the central plane and extending substantially radially outwardly from the outer annular wall. The cover includes sidewalls disposed on lateral sides of the rim adjacent the projections, each sidewall including a lateral inner portion having a lateral thickness. The cover further includes an annular ring portion interconnecting the sidewalls, the annular ring portion including a radial thickness less than the lateral thickness of the lateral inner portion of the sidewalls. Preferably, the rim comprises a metallic material and the cover comprises a non-metallic material. For example, the rim can comprise aluminum or an epoxy matrix composite, and the cover can comprises a polymeric material, such as ultra-high molecular weight polyethylene. In addition, a radial thickness of the entire cover is preferably substantially less than a radial thickness of the entire rim.In one embodiment, the projections include a laterally inwardly facing surface, a laterally outwardly facing surface, and a radially outwardly facing surface. In this embodiment, the cover engages at least a portion of each of the laterally inwardly facing surface, the laterally outwardly facing surface, and the radially outwardly facing surface. Preferably, each annular projection has a smoothly radiused radially outwardly facing surface, and each laterally outwardly facing surface that lies in a radial plane substantially parallel to the central plane.