The characterisation of bicycle tyres and their impact on event performance for athletes of differing abilities
Billy Fitton, PhD-cand
Engineering Design Group, Cambridge
Time & Place
Fri, 24 Nov 2017 11:00:00 NZDT in E12
In order to accurately simulate the performance of a cyclist the behaviour of bicycle tyres must be understood. A test rig has therefore been designed that can be used to measure the performance characteristics of bicycle tyres. The rig has a pivoted arm mounting the bicycle wheel so that it rolls on a drum driven by a motor with a torque measuring device. Both lateral (side) and longitudinal (rolling resistance) forces can be determined. The effect of camber angle, slip angle, wheel velocity and normal load on various tyres has been investigated using this test rig. The rolling resistance coefficient, cornering stiffness and camber stiffness of different tyres has been compared. In an example application of the measured tyre data the impact of handling ability on race performance has been simulated. The results from the tyre testing rig have been used as inputs to a simple mathematical model of cycling to estimate the effect of tyre choice and athlete steering ‘wobble’ on performance. Results from this study suggest that both steering ‘wobble’ and tyre choice can have a significant influence on the finishing time of athletes competing in either a 4 km Individual Pursuit or a 40 km time-trial.