Letter regarding recommended tyre pressures for a Phantom 'Three' car to improve non-skid performance.
| Identifier | ExFiles\Box 156\3\ scan0042 | |
| Date | 7th February 1936 | |
| Copy for Mr. Robotham, Experimental Dept. Messrs.Rolls Royce Ltd. Derby. WMR/EW Friday, 7th February, 1936. Messrs. Rolls Royce, Ltd., Seagrave Road, Fulham. For the attention of Mr. Crawford. Dear Sirs, With reference to the interview which you kindly gave me last Monday on the subject of a set of our 7.00/18 Supreme Tyres tested on a Phantom "Three" 12 cylinder Rolls Royce car, I have been comparing our pressure schedules with the pressure at which you kindly conducted these tests. The car weight being 2tons 11 cwts. and assuming that this is equally proportioned, then our recommended pressure would be 32 lbs. per square inch. We feel very definitely that any increase over this figure would be considerably reducing the non-skid properties of the tyres. From an inspection which I made of the tyres, it certainly seemed to me that the X formation on the side pattern which accounts for a great deal of non-skid effect, was not contacting properly, and we believe that a pressure of 32 lbs. will entirely cure this trouble. We hope that you may see your way clear to give these tyres a further test at the revised pressures, and | ||
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).