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 the Dunlop Rubber Co. requesting figures on the rolling resistance of various tyre types.
| Identifier | ExFiles\Box 45\1\ Scan347 | |
| Date | 30th October 1925 | |
| /4050 L459 Hs{Lord Ernest Hives - Chair}/Rml/LG. Expl: Dept: 30th. Oct. 1925. Messrs. The Dunlop Rubber Co., Fort Dunlop, Erdington, Birmingham. Dear Sirs, For the attention of Mr. Healey. Research Section. We sent off the 6 tyres as requested per bearer yesterday. We are interested in the respective merits of soft and hard tyres, traction and new type tread, balloons and high pressure with regard to petrol consumption. We wonder whether you have any figures as to the rolling resistance of these tyres in lbs. per ton load upon them which you could give us. We find in our tests that the rolling resistance of the tyres increases very greatly when the tyre is cold, and steadily increases [typed above 'decreases' which is struck through] until it has attained its maximum temperature. This is especially noticeable in an under-inflated tyre. We should much appreciate any information you may have on this subject. Thanking you in anticipation. Yours faithfully, | ||