Development of Aluminum Alloy Frame of Motorcycle for Motocross

High rigidity and light weight properties of the frames and swing-arms of motorcycles for motocross are requested. A twin-tube type frame using newly developed aluminum alloy having tensile strength of 450MPa and a tapered swing-arm made by a new manufacturing method have been developed. As a result, the weight of the frame and swing-arm was reduced by 2000g and the lateral rigidity and torsional rigidity of the frame were achieved at 2 times and 1.7 times compared with the previous models, and improve driving stability and acceleration.