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).
Steering wobble, tyre pressures, and wheel balancing based on test results and customer instruction.
| Identifier | ExFiles\Box 67\3\ scan0205 | |
| Date | 20th August 1925 | |
| try30 BJ17/H20.8.25 (Noon). To C.J. from B.J. Copies to By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} STEERING. In the memorandum dictated at 10-30 a.m. and read to you on the telephone this morning, I mentioned that C.F.N. had experienced no wobbles during the last 500 miles on our demonstration car, with the tyres at 55-lbs. pressure and balanced wheels. I have just received a telephone message from By.{R.W. Bailey - Chief Engineer} and Hs.{Lord Ernest Hives - Chair} that they agree that no wobbles have been experienced with any car fitted with balanced wheels and tyre pressures over 50 lbs. This includes all the tests made in France. The cars tested in France had front tyre pressures of 50 lbs. or more, as they were to run at high speeds. It seems a pity that cars should be tested for 10-000 miles under non-standard conditions (which differ from our advice to customers in our Instruction Book, which is lbs*) Should we not advise them in future to make their tests in exact accordance with instructions we give customers, including tyre pressures, lubrication, &c to?) I telegraphed you to-day, therefore, as follows:- "Hives and Bailey agree perfectly safe issue cars provided customers are advised to keep front tyres at over fifty pounds pressure and wheels balanced No trouble in all tests made in France and elsewhere with tyres over fifty pounds pressure Northey considers fifty to fiftyfive pounds reasonably comfortable Possibly fiftyfive pounds is safest pressure to quote customers have stopped deliveries pending your decision." B.J. * Front tyres (closed cars) 55 lbs. per sq. inch. Front tyres (open cars) 45 lbs. per sq. inch. Rear tyres (closed cars) 65 lbs. per sq. inch. Rear tyres (open cars) 55 lbs. per sq. inch. | ||