PURPOSE: To realize the safe traveling performance by preventing embedding of wheels, deterioration of the steering performance associated with the reduction in the frictional resistance, and deterioration of the braking performance in a bad road.

CONSTITUTION: A bicycle has a structure where a sled is mounted on the side of a front wheel of a bicycle, and a caterpillar belt 2 is mounted on a rear wheel as the driving wheel, and the structure consists of a guide gear 1 to keep the tensile strength of the caterpillar belt 2, a front stay 3 having a hinge mechanism to support the guide gear 1, and a rear stay 5 having the suspension to absorb the shock, and the structure is designed so as to prevent embedding of the tires in the traveling road surface and increase the contact area of the tires with the road surface.