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 power losses, expressing frustration with Dunlop and comparing the performance of India and Avon tyres.
| Identifier | ExFiles\Box 158\2\ scan0014 | |
| Date | 18th May 1939 | |
| 1339 To By.{R.W. Bailey - Chief Engineer} c. to Ha. c. to Da.{Bernard Day - Chassis Design} c. to Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} Rm.{William Robotham - Chief Engineer}8/JH.18.5.39. Tyre Losses. We are disgusted with the lack of technical initiative displayed by the Dunlop Rubber Co. In spite of frequent requests, they have never given us reliable power loss figures on any tyre. Considering that, as will be seen from the attached report, a set of new India tyres on a Bentley absorb 60 B.H.P. at 100 m.p.h. and we worry about 2 H.P. loss on an intake silencer, we decided to make the necessary apparatus to demonstrate to the tyre companies the error of their ways. This we are now doing, thanks to our road wheel dynamometer equipment. The results obtained have been confirmed by track tests. It is satisfactory to note that the Avon tyre is about 20% better than the India for power loss under all conditions. Rm.{William Robotham - Chief Engineer} | ||