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).
Letter to Doctor Mackay of The Avon India Rubber Co., Ltd., detailing the results of comparative tyre tests.
| Identifier | ExFiles\Box 156\3\ scan0259 | |
| Date | 26th May 1941 | |
| FILE 1331 Rm.{William Robotham - Chief Engineer}2/SW. 26th May, 1941. Doctor Mackay, The Avon India Rubber Co., Ltd., Merksham, WILTS. Dear Doctor Mackay, We have now done some comparative tests on your modified Avon tyres, and compared them with the latest India tread. The India tyre is our standard for freedom from squeal. We find as a rough comparison, that on a given surface and radius of bend which we have locally, the respective squealing speeds of the two tyres are 20 & 24 MPH. In addition to squealing at a lower speed, the Avon tyres also make a more penetrating noise. In their favour, your tyres are less prone to "groaning" at speeds below 20 MPH. If you would like to discuss these results I suggest tentatively Friday, May 30th of next week. At the same time, we might also talk about American rim practice. Yours sincerely, | ||