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 discussing tyre performance, racing records, and refuting claims of steering wobble at high speeds.
| Identifier | ExFiles\Box 28\4\ Scan220 | |
| Date | 18th December 1924 | |
| -2- and drivers interested in racing. In six months, every world's record, including all those which have stood since 1913 - from One Mile to 1800 Kilos - have been broken on these Oversize tyres. The speeds range from 95 to 145 miles per hour. You are no doubt aware that I personally am the owner and part-driver of the 40 HP. Lanchester car which holds more World's and Class records than any other, some seventy two in all. As I am the holder and personally drove in the successful attempt on the World's Twelve Hour record in which an average was recorded of over 95 miles per hour (which meant lapping continuously at 100 miles per hour to allow for stoppages), I trust you will accept my word that no sign of steering wobble occurred from start to finish. This statement can be confirmed by Messrs. Lanchester who were present. To enlarge on foregoing, I do not think I can do better than refer you to a letter from Mr. Louis Coatalen, the Director and designer of the Sunbeam, Talbot, Darracq racing cars which swept the board with practically every international event during the past racing season. Mr. Coatalen writes as follows:- "With regard to races of importance, it is perfectly obvious that the serious participant will not be induced by any bonus whatever to use something in which he does not believe. For instance, no premium could have made me replace the Rapson tyres used on the Sunbeam and Darracq racers this year with any other make of tyre in the world. I instituted the most rigorous tests of all the tyres available. Rapson's came out far and away the best, and, therefore, they were adopted." You have no doubt seen from time to time letters in the technical motor journals from other prominent designers and race drivers who are equally emphatic as to the efficiency of the Rapson tyre when used at high speeds. It is because of these things that I am naturally at a loss to understand why our tyres should cause steering wobble on one of your most important customer's cars when driven at speeds the maximum of which I believe to be 75 miles per hour, which is substantially one-half that officially recorded on Mr. E.A.D. Eldridge's Fiat when breaking world's records recently over in France. - The problem is still more puzzling in view of other trials which you have conducted on your own cars. - In the first instance your own reports prove that on your 20-HP. model, our re-tread tyres have more than doubled the previous best average mileage you ever got from any other make and nothing whatever is stated in these reports regarding steering wobble. - Again over in France, when subjected to comparative trials against Dunlop tyres, your report shows that we returned 12½% better average mileage results and again no steering trouble was experienced. | ||