Abstract: A wheel assembly for a vehicle includes a wheel having a first rim half and a second rim half secured together to form an annular outer rim for receiving a tire. The rim halves have aligned central openings and aligned apertures for receiving fasteners for mounting a wheel hub on the wheel. In one embodiment, at least the central opening of one of the rim halves includes a plurality of spaced recesses around its periphery. A rock guard built into the wheel includes a plurality of rock guard formations each forming a shield which fills at least a major portion of any space between a respective recess and the wheel hub to block at least some debris from passing through the wheel while allowing airflow through the wheel.