Influence of Antilock Brakes on Motorcycle Braking in a Turn 891773

A theoretical and experimental investigation of the effects of antilock braking (ALB) on motorcycle braking in a turn (BIT) is described. The analyses involved computer simulation of the dynamic interaction among rider, motorcycle, ALB, and roadway during BIT maneuvers; and instrumented full scale BIT tests with expert and novice riders. The analyses and full scale tests used an example all mechanical, independent front and rear ALB system. The results showed that ALB can help maintain motorcycle stability in straightline and gradual turns at high and excessive brake force levels. In more severe turns, the motorcycle can capsize at low brake force levels, below those which are typically needed to trigger ALB operation. As a consequence, from a fundamental standpoint, contemporary conventional ALB systems cannot be considered to influence or improve motorcycle stability during limit braking in moderate or near limit turns. At the same time, the results show that the ALB can enhance stability during limit braking in straightline or gradual turns. Also, stopping performance can be improved, especially during combined front and rear brake operation, due to simplification of the rider's control task. However, in other situations, some reduction in stopping performance can occur, for example, during full ALB cycling, compared to best non ALB stops. Overall, these results confirm that ALB is not a panacea, but instead represents a balance among a variety of stability and performance factors.