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).
Technical discussion on tyre performance, including pressure, fitting, tread patterns, and noise issues.
| Identifier | ExFiles\Box 42\5\ Scan017 | |
| Date | 1st September 1920 | |
| Contd. -3- Hs{Lord Ernest Hives - Chair}2/LG1.9.20. Even if it is proved that the tyres last longer with high pressure, we think we have still to reckon the extra wear and tear on the chassis due to the hard tyres and the loss of comfort. If we can, as we believe, prove that a tyre pumped to 65 lbs. pressure approx. will last as long, if not longer than one pumped to 85 lbs. we ought to recommend that tyres on R.R. cars are kept at that pressure. With reference to your memo. R5/G20.8.20. complaining that the straight-sided tyre which you had occasion to change on 1.EX was very tightly fitted on to the wheel. Our experience shows that all Kelly springfield tyres are tightly fitting. The Firestone comes the next as regards tightness; the Goodyear, United States Royal Cord, Goodrich Cord and Dunlop straight-sided tyres are all very easy to fit on the wheel. They fall off as soon as the detachable flange is taken away. We agree, there does not appear to be any necessity for a straight-sided tyres to be tightly fitting on the wheel. X.3926. Another point to be watched as regards tyres, is the pattern of the tread. The diamond shaped knobs on the Goodyear straight-sided tyres are smaller and not so deep as those on the Clincher tyre. They do not have that same fault as regards causing the car to be unstable. Another point which has come up lately is the the noise which is caused by tyres. We have frequently had complaints from customers as regards noise which we have been able to prove is due to the tyres. The Dunlop Magnum Contd. | ||