In a motorcycle with a swing arm disposed on one side of a rear wheel for supporting the rear wheel. The swing arm is formed in a roughly triangular shape in a side view and a brake caliper of a rear brake is supported by the swing arm. The brake caliper is disposed relative to the rear brake so as to contrive a lowering of the center of gravity of the motorcycle and to enhance the rigidity of the swing arm. An opening portion is provided in a roughly central portion of a swing arm and a brake caliper is disposed in the opening portion.