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 from Dunlop Rubber Co. providing data on tyre wear rates and mileage performance for different tyre sizes and seasons.
| Identifier | ExFiles\Box 53\2\ Scan261 | |
| Date | 6th October 1926 guessed | |
| YL565 DUNLOP RUBBER CO.,LTD. TELEGRAPHIC ADDRESS: "DUNLOPS, BIRMINGHAM" TELEPHONE: BIRMINGHAM CENTRAL 4108 P.B.E. 25 LINES YOUR REF: Hs{Lord Ernest Hives - Chair}/Rml/T. OUR REF: AH/HR. Mr. Paull's Office. FORT DUNLOP ERDINGTON BIRMINGHAM Messrs. Rolls-Royce Ltd. DERBY. Experimental Department. For the attention of W.A. Robotham. Dear Sirs, In reply to yours of the 30th. September, we have collected all the available figures on the rate of wear of 33 x 6.75 tyres and 33 x 5 tyres. The average result is given below:- 5" 6.75" REAR 930 1085 FRONT. 1450 1390 These figures represent the number of miles given by the tyre for wear of 1 mm. of tread depth. In respect to atmospheric conditions, we observed very closely the performance of nearly 800 tyres of various sizes, and found that the average winter wear was nonly half that of the average summer wear. That is to say, tyres give twice the mileage in winter as than in summer. We shall be very glad indeed to receive any information that you can give us on this subject. Yours faithfully, For the Dunlop Rubber Co., Ltd A Healey | ||