Abstract
It is thought that the first step to understanding vehicle movement is to measure and analyze that movement in order to confirm that it falls within the range of the laws of physics. In the case of a four-wheeled vehicle, in general, the friction limit is defined within the circle of longitudinal acceleration and lateral acceleration through the use of a G-G diagram. Then measurements are taken to confirm that the driving state is within that range. G-G diagram was applied to a two-wheeled vehicle. Measurements were also taken during actual motard riding by top-class Japanese motard motorcycle riders. It was confirmed that this measurement data was distributed within the range of the friction circle. Consequently, it was confirmed that it is possible to use G-G diagram to accurately grasp the vehicle movement limits and the associated driving state for two-wheeled vehicles.
