The principal factors likely to affect the rolling resistance of tyres were identified in TRRL Supplementary Report 192 UC as:- inflation pressure, load and deflection, tyre construction and material hysteresis, tread depth, slip and camber angles, temperature, speed and the road surface. The effect on commercial vehicle tyres of a majority of these factors has since been investigated. The results of the investigation are given and discussed in this report and broadly support the earlier conclusion, showing that tyre rolling resistance decreases significantly with change in construction (cross-ply to radial ply) and increases significantly with increase in slip angle. However, for a given construction tyre deflection has been determined as the principal factor controlling rolling resistance, indicating that the chief source of energy loss in a tyre is attributable to hysteresis. (Author/publisher)
Abstract