Abstract: A bicycle wheel has good impact properties and increased durability. In one embodiment the rim comprises a two piece rim having a carbon fiber based body portion having bulbous sidewalls for capable of flexing in response to radially directed forces, and a tire engaging, hoop-like rim made from aluminum. The rim includes a pair of parallel braking surfaces. In the preferred embodiment, the convex curved sides of the wheel, in transverse cross section are wider than the braking surfaces and intersect the braking surfaces at an angle of less than about 175.degree..