Letter from Dunlop discussing the results of tyre deflection tests on different rim sizes and the return of a loaned tyre and wheel.
| Identifier | ExFiles\Box 157\1\ scan0288 | |
| Date | 3rd April 1936 | |
| GRY. {Shadwell Grylls} X1332 DUNLOP RUBBER CO.,LTD. TELEGRAPHIC ADDRESS: "DUNLOPS, PHONE, BIRMINGHAM." TELEPHONE: BIRMINGHAM CENTRAL 4108 (P.B.E.) EXTENSION No. 349. YOUR REF: OUR REF: LJL/G.101. FORT DUNLOP ERDINGTON BIRMINGHAM April 3rd, 1936. Messrs Rolls Royce Ltd., Experimental Department, DERBY. For the attention of Mr Grylls. Dear Mr Grylls, As promised on my visit on Wednesday last, we have compared the deflection of the 7.00-18 Fort '90' tyre at a range of loads and pressures when fitted on a 5.00 and 4.00 rim. The attached graph, DDS.6284 shows that the wider rim has approximately the same effect as 3 lbs increase in inflation pressure. I say approximately, because unfortunately, the tyre and wheel which you loaned us was just too big to go in our ordinary deflection machine, which meant that we had to test it in a machine which is not so sensitive for small loads as that normally used for car tyre work. However, you can take it that the results are of the right order and we shall make a further check when we obtain from our Rim and Wheel Works an experimental 5.00-18 rim which we have now ordered. (We shall be able to get this tyre and rim on our ordinary deflection machine). We have returned to-day by one of our test cars, the tyre and wheel which you loaned to us on Wednesday. Presumably Mr Robotham will get in touch with Mr Price if you require definite information regarding the continuity of supplies of these wheels. Yours faithfully, For THE DUNLOP RUBBER CO. LTD. L. J. {Mr Johnson W.M.} Lambourn Product Design Division. | ||
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).