Exploring bicycle braking during a descent

Abstract

This exploration study focuses on the braking behaviour of World Tour cyclists during a descent. For this study, 8 riders descended over 6 trials using a ‘sensor bike’. As part of this particular study, a novel brake sensor is developed and validated in practice. The sensor package can be transferred between bicycles, allowing each rider to use his own bicycle. Results of the exploration study indicate that for the chosen descent, braking and cornering skills are not decisive for overall time over the descent. However, significant time differences are found for the corner which is analysed. Time difference reported over this corner are approximately one second. With a shortest cornering time of 10.14 seconds this is a significant difference. The brake behaviour of theWorld Tour cyclists could be split into two distinct braking strategies: • ’stop brake late’ ( where braking is stopped late and well into the turn). • ’stop brake early’ (where braking is stopped before or early in the turn). It was found in this study that the best brake strategy is ’stop brake late’. The peak brake forces measured during the descent are much lower than the maximum brake forces reported in literature. This implies, that performance can still be improved by increasing brake forces at the first part of the braking action, so the braking can start later. The results found in this study can contribute to optimise braking and cornering skills of riders by explaining and showing where improvements can be found. An additional result is that the brake sensor revealed unexpected brake rub at certain parts of the descent, especially when riders are accelerating. Eliminating this brake rub, can improve rider performance. The riders also shows clear signs of learning behaviour as can be observed in the obtained data. For future research it is recommended to add a speed sensor to the sensor package. Recommended small improvements for the brake sensor are identified. Using this improved sensor package, trials could be rehearsed on a steeper descent, such that pedalling actions have less influence, exploring braking and cornering strategies further.