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 Goodyear Tyre & Rubber Co. regarding the benefits of low-pressure cord tyres.
| Identifier | ExFiles\Box 39\2\ Scan098 | |
| Date | 30th September 1921 | |
| COPY. Hsl/LG 30th. Sept. 1921. The Goodyear Tyre & Rubber Co., 162, Shaftsbury Avenue, London W. C. 2. Dear Sirs, For the attention of Mr. E.{Mr Elliott - Chief Engineer} R.{Sir Henry Royce} Preston. We should like to have your opinion as regards tyre pressures which you recommend for your straight-sided cord tyres. From the result of a number of tests we have carried out we consider that with the cord tyre the life of the tyre is not depreciated if a lower pressure is used compared with a fabric tyre. On our tests with all makes of cord tyres, the outstanding advantage with the cord tyre is freedom from bursts. We have not had a single case of a cord tyre bursting until the tread has been worn away. Careful tests which we have made have proved that with the cord tyre we actually get more mileage with the low pressure than with a high pressure. This we attribute to the fact that when a high pressure is used the axle bounces about on the road and the tread is scrubbed off. It is our opinion that as long as the casing of the tyre does not burst there can be no other harm caused to the tyre due to low pressure. You are no doubt aware of the tremendous difference in the comfort in the riding of a car with low tyre pressure compared with high tyre pressures. We could not ever recommend tyres to our customers in which the makers demand shall be pumped to high pressures. The tyres of your make which we have been testing we have run from 45 to 50 lbs. on open-touring cars and 55 to 60 lbs. on closed cars. We have not had a single burst, therefore we consider we are justified in using these low tyre pressures. We should be very pleased to have your views on this matter. Yours faithfully, | ||