Motion analysis of a motorcycle in straight riding and turning at high speeds by dynamic model considering compliance of frame component

This paper presents an analysis of the motion of a motorcycle at high-speed using a motorcycle dynamics model that considers the compliance of the frame components. Several motorcycle nonlinear dynamics models have been proposed in previous studies and in the industry. However, these models do not consider the compliance of the frame components, which affects the maneuverability and stability of motorcycles. Moreover, there is not any researches that analyzes the effect of such compliance on motorcycle dynamics in a domain that includes turning. In this paper, we derive a nonlinear dynamics model of a motorcycle that takes into account the compliance of the frame components and analyze the effect of such compliance on the vehicle body motion during high-speed straight riding and turning. For the dynamics model, the Kane’s equation is constructed based on multi-body dynamics analysis. In conclusion, we demonstrate that the compliance corresponding to the lateral torsion of the front forks is the most dominant factor in improving stability in the high-speed region, both in straight riding and in turning.