Steering compensation for high-performance motorcycles

This paper introduces the idea of using a mechanical steering compensator to influence the dynamic behaviour of a high-performance motorcycle. The compensator is seen as a possible replacement for a conventional steering damper, and comprises a network of a spring, a damper and a less familiar component called the inerter. The inerter was recently introduced to allow the synthesis of arbitrary passive mechanical impedances, and finds a new potential application in the present work. The approach taken here to design the compensator is based on classical Bode-Nyquist frequency response ideas. The vehicle study involves computer simulations, which make use of a state-of-the-art motorcycle model whose parameter set is based on a Suzuki GSX-R1000 sports machine. The study shows that it is possible to obtain significant improvements in the dynamic properties of the primary oscillatory modes, known as "wobble" and "weave", over a full range of lean angles, as compared with the standard machine fitted with a conventional steering damper.