Letter from Dunlop discussing tyre cornering tests and the effects of rim width and pressure.
| Identifier | ExFiles\Box 157\2\ scan0022 | |
| Date | 11th August 1936 | |
| DUNLOP RUBBER CO.,LTD. TELEGRAPHIC ADDRESS: "DUNLOPS, PHONE, BIRMINGHAM" TELEPHONE: ERDINGTON 2121 (P.B.X) EXTENSION No. YOUR REF: Exptl Dept. OUR REF: FORT DUNLOP ERDINGTON BIRMINGHAM Handwritten notes: X1332 GRY. {Shadwell Grylls} ANY OBJECT IN DISCUSSING Rm. {William Robotham - Chief Engineer} August 11th. 1936. W. A. {Mr Adams} Robotham Esq., Messrs. Rolls Royce Ltd., Derby. Dear Robotham, Our Research Laboratory have been carrying out some tests on cornering power at low speeds, and have established first of all that notwithstanding low speed, the tests bring out differences which we believe would occur when cornering on the road. For instance, it has been established that a wider rim (4.00 instead of 3.25) gives about the same effect as 25% increase in pressure. Also, that a tyre of special construction which is very much inclined to wander on the road and to give a feeling of uncertainty in driving, is much inferior to the normal tyre on this particular test. Although our tests are made at low speed, and show differences between a wide rim and a narrow rim, and between high and low pressures, it is thought that these differences may become more apparent to the driver if cornering is done at really high speeds, say between 50-60 m.p.h. The sizes used were 5.25/18 and 6.00/18. You will remember that the tests made by R.D. Evans (Goodyear) proved that the effect of speed was quite small. The cornering force-slip angle curve we obtained was of the same shape as Evans'. I shall be glad to know if this work is proving of assistance to you, and whether you would like to have a joint discussion on it at an early date? I am going for a holiday at the end of this week, and if you think there is need for it, I could come over to see you in the meantime. Yours sincerely, A Healey | ||
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).