The mounting is a tripod, but the front leg has a castoring wheel.

The fiberglass gear legs support castoring wheels in the front, allowing for conversion to floats and providing support when the tail section is swung open for cargo loading.

Fixed undercarriage legs were designed specifically for vertical flight with each leg carrying a pair of castoring wheels (the rear undercarriage was also fitted with disc brakes).

The undercarriage of the Avrocar was rudimentary with three small castoring wheels mounted on "stub" shafts; a set of skids was substituted later in testing although they were not normally fitted.

Powered wheels are typically somewhat larger than the trailing/castoring wheels, while castoring wheels are typically larger than the castors on a manual chair.