A wheel holder assembly includes a mounting frame fixedly fastened to the footplate of a skateboard, a screw bolt mounted in the mounting frame, a hook plate mounted on the screw bolt and hooked on a barrel at the mounting frame, a swivel wheel holder frame mounted on the screw bolt to hold a pair of wheels, a first corrugated washer and a second corrugated washer mounted on said screw bolt and matched with each other between the hook plate and the wheel holder frame, the first corrugated washer having a locating groove engaged with a locating rib at the wheel holder frame for enabling the first corrugated washer to be turned with the wheel holder frame about the screw bolt relative to the second corrugated washer, and a compression spring mounted on the screw bolt to force the wheel holder frame against the first corrugated washer.
The skateboard wheel and axle assembly includes an axle rigidly mounted in a hangar, with opposite ends of the axle extending from the hangar. Each end of the axle has an axial blind bore defined therein closed by an end cap and a plurality of holes defined radially adjacent the end cap. A spring-biased detent pin slidably mounted in the bore urges a plurality of detent balls to partially extend from the radially disposed holes. The detent balls engage an annular groove defined in the inner race of the outer wheel bearing to retain the wheel on the axle. The detent pin has a release arm extending through aligned slots in the axle and the hangar that can be retracted, compressing the bias spring, in order to withdraw the detent balls from the groove so that the wheel can be pulled off the axle.