Vibrations Investigation (using mountain bike damping system)


This purpose of the experiment was to better understand the dynamics of bike suspension systems, which are designed to allow vertical movement to die away in order to provide a more comfortable and secure ride when traversing rough terrain. The exact ‘best’ damping and stiffness ratios are largely down to personal preference, so the configurations used vary slightly, and so in this lab multiple compression and extension rates of damping were tested, with and without springs, for multiple speed settings (representing the difficulty of the terrain). While a broad agreement with the idealised theory of these systems could be seen, discrepancies were evident, such as the compressional effects of air and environmental (e.g. temperature) effects on the dampers, which are discussed in the report, as well as experimental errors in the setup. It could also be noted that the spring constant (69900N/m) was found to be around 14% higher than the stated value, which may indicate an inaccurate labelling of the pieces of the damper. It could also be seen that generally bikes tend to have higher damping coefficients in rebound than bounce, and the effect of turning the dials on the damper was to increase the damping coefficients.


Due to the lab being repeated for other years, the full report has not been uploaded. It is however available on request, using the contact details available.