From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Tyre failures, comparing tyre loss on drums versus the road and the performance of different tyre types.
| Identifier | ExFiles\Box 97\3\ scan0178 | |
| Date | 3rd July 1939 | |
| -3- Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden}/3/JB.3.7.39. From these figures it is seen that the theory of 1 1/2 times greater tyre loss on the drums than on the road is still held true. Tyre failures. Attached is a more or less self explanatory chart of the tyre failures which occurred. All these failures were due to the tread being either completely thrown or loosened. All the tyres were new except the India which had completed a small mileage but had scarcely lost any of their tread. The Avon light tread was slightly better than the medium and heavy at road pressures. When pumped up to 40 lb.in.2. the Avon light tread tyre showed no signs of becoming unduly hot, and would apparently last indefinitely under road conditions at high speed. Even when they started life at higher pressure, however, the heavy tread tyre did not last 40 miles with two stops. Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} | ||