Abstract: There is provided a new and useful wheel assembly incorporating a brake mechanism for mounting on the frame or base of a skateboard or a roller skate comprising a truck for attachment to a roller skate or skateboard, a first axle secured on the truck, a pair of wheel supports mounted on the first axle for rotation relative to the first axle, a first wheel mount on the wheel supports forward of the first axle for carrying a pair of forward wheels mounted thereon, a second wheel mount on the wheel supports rearward of the first axle and having at least one rearward wheel mounted thereon; and frictional brakes fixed to the first axle, the brakes positioned such that a predetermined amount of rotation of the wheel supports relative to the first axle will bring the brakes into contact with at least one of the wheels.