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).
Comparison of different tyre tread patterns and their associated noise and wear characteristics.
| Identifier | ExFiles\Box 42\5\ Scan042 | |
| Date | 10th October 1925 guessed | |
| To Hs{Lord Ernest Hives - Chair} OLD GOODRICH. (Quiet & stays quiet). Section A.A. NEW GOODRICH. (noisy + gets noisier in 5000 miles). Section A.A. wear occurs thus giving polygonal shape to tyre thus:- AM. DUNLOP. (Fairly quiet & appears to stay quiet). | ||