An auxiliary side wheel assembly for use with a two wheel vehicle, such as a motorcycle, is shown which includes right and left arms at opposite sides of the vehicle which arms are attached to a connecting shaft extending transversely of the vehicle. The arms extend downwardly and rearwardly from the connecting shaft and are provided with left and right ground engaging auxiliary wheels at the lower ends thereof. A releasable lock engagable with the auxiliary wheel assembly releasably locks the same against upward pivotal rotation about the connecting shaft. In the locked condition, the vehicle is stabilized to prevent tipping onto its side, which stability is of particular benefit during low speed operation and when the vehicle is stopped.
