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 Dunlop Rubber Co. Ltd. discussing tyre and rim tests for cornering power.
| Identifier | ExFiles\Box 157\2\ scan0023 | |
| Date | 12th August 1936 | |
| 1332 Expl. Dept. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}9/MJ. 12th. August, 1936. The Dunlop Rubber Co. Ltd., Fort Dunlop, Erdington, BIRMINGHAM. For the attention of Mr. A.{Mr Adams} Healey. Dear Sir, Mr. Rowbotham has asked me to reply to the technical points in your letter of the 11th. inst. We are glad to know you have found that the increased cornering power you can measure on your test apparatus is consistent with what we notice when driving a car on the road. Primarily of course we are interested in achieving a wheel that gives the maximum cornering power for a given degree of discomfort. On our Phantom lll car we are satisfied with the comfort of the 7/18 tyre on a 4" rim at a pressure of 35 lbs. On the Bentley we have a 5½" tyre on an 18/3.62 rim at 30 lbs. pressure. We do not know if it is asking too much for you to do a series of tests on all rim sizes up to 1" less than the section of the tyre in order to determine the optimum condition. If, of course, very little increase is obtained by the last ½" in rim width and the increased weight of the rim is considerable we should be satisfied with slightly less than the maximum cornering power. We hope you will be willing to do these tests for us and would add once again that if we can help by lending you an axle or wheels we should be very glad to do so. | ||