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 a tyre company asking for their views on the difference in cornering power between 4-ply and 6-ply tyres.
| Identifier | ExFiles\Box 157\6\ scan0189 | |
| Date | 27th January 1938 | |
| 1336 Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}9/MH.{M. Huckerby} P.Worth, Esq., The India Tyre & Rubber Co. Ltd., Inchinnan, SCOTLAND. 27th. January 1938. Dear Mr.Worth, We have noticed that no car in America, other than the two or three largest, uses more than a 4 ply tyre. In the past we have had to use 6 ply tyres to prevent tramping, but now since the advent of independent suspension wonder whether 6 ply is justifiable. What we do not know is how the cornering power is affected by the number of ply. If you could send us two each of 16" or 17" tyres having exactly the same pattern, but in one case 4 and the other 6 ply, we could measure the cornering ability on our Skid pan. Perhaps you would send us your views on this matter. Yours sincerely, | ||