Abstract: A motorcycle provided with a central trunk and left and right trunks at the rear portion of the vehicle body. The vehicle body frame of this motorcycle is composed of a main vehicle body frame at the front and a rear vehicle body frame that can be detachably mounted to this main vehicle body frame. The rear vehicle body frame constitutes a trunk assembly jointly with a central trunk, a left trunk, a right trunk and other equipments such as lamps, and after the above-mentioned trunk assembly has been formed preliminarily as one unit outside of a main assembly line, it is detachably mounted to the main vehicle body frame on the main assembly line. Accordingly, the work on the main assembly line becomes little and simple, and a productivity is improved. Upon replacement of a rear wheel tire, it is only necessary to dismount the entire trunk assembly together with the rear vehicle body frame without individually dismounting a large number of equipments.

Abstract: A heated air ducting structure (20; 200; 300; 360; 400) for motor cycles (50; 350; 450) including an engine (2; 302) mounted at a lower position in the front part of a vehicle body frame (1) and a a rider's seat (4; 401) installed on the vehicle body frame behind the engine. The ducting structure comprises a duct (20a; 208, 208r, 205a, 205c; 321, 314; 361, 365; 404, 405, 409) having a heated air entry (20b; 208c; 322; 362; 407) which, facing a rear portion (2b; 302g) of the engine, takes in heated air that has cooled the engine, and a heated air exit (20c; 205f; 328; 365b; 409b) which opens in the rearward direction of the vehicle.

Abstract: A water-cooled engine cooler of the divided type for such vehicles as autobikes, autotricycles, four wheel buggy, etc., is disclosed. The cooler has two radiators for cooling the water-cooled engine, these radiators being inclined with respect to the direction of progress of the vehicle such that their axes extending at right angles to their front intersect with each other at a forward position of the radiator.