STATIC AND DYNAMIC STIFFNESS AND DEFLECTION MODE MEASUREMENTS ON A MOTORCYCLE, WITH PARTICULAR REFERENCE TO STEERING BEHAVIOUR

A comparison between two different methods of determining the stiffness of a motorcycle frame is made. The first employs conventional, static loading of the frame with deflections and mode shape measured by dial gauges. The second entails dynamic loading of the frame by means of a sinusoidally driven shaker with deflections obtained by means of an accelerometer, electronic data processing then yielding frequency response information. Conclusions are drawn about the implications for accurate modelling of motorcycle steering behaviour arising from differences between the static and dynamic properties of the frame.