An underbone motorcycle is a small motorcycle built around a single tube frame called the underbone. This ‘underbone’ supports the whole vehicle and runs low all across the length of the motorcycle. There is a similarity in appearance to the scooter, largely due to the fuel tank position, the open-frame design which the fuel tank position allows and the splash guards. However, the entire power train, namely the engine position, power transmission and wheels are based on the design of conventional motorcycles.