Motorcycles arrange the radiator in front of the engine. So, the size of radiator is not wider than the width of engine or the width of frame. We design the motorcycle similar to road-racer. We hope that the width of radiator is as narrow as possible, because motorcycle can run as fast as possible. So, it is necessary that the width of engine and frame is narrow as much as we can, and the width of radiator is limited.But for the water-cooled engine, the temperature of coolant has better be low so as to product the effective combustion. So, it is necessary that the width of radiator has better be wide, but it contradict the above.“U-Shaped Radiator” solves the above problem. The structure is that radiator bends U-form in the front of motorcycle. Now we can improve the cooling performance (+30%) in comparison with the same width radiator.