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).
List of five factors that do not appear to affect tyre noise.
| Identifier | ExFiles\Box 156\3\ scan0033 | |
| Date | 30th October 1935 guessed | |
| -4- Tyre noise does not appear to be affected by the following :- (1) Different types of wire wheels. (2) Disconnecting shock dampers from axle to frame. (3) " roll bar " " " " (4) " all brake ropes from axles. (5) Removal of wings. | ||