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).
The initial testing of Dunlop super-cushion tyres.
| Identifier | ExFiles\Box 53\2\ Scan021 | |
| Date | 17th August 1923 | |
| R.R. 403A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 4565 REF: Hs{Lord Ernest Hives - Chair}3/LG17.8.23. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to DJ. E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} CY. RE. SUPER-CUSHION TYRES. We have received from Messrs. Dunlop a set of wheels fitted with super-cushioned tyres. The tyres they have supplied us with are bigger sectioned and can be run with much lower tyre pressure than the tyres mentioned in OY2/W8423. The tyres we have are 8" section - the rolling dia. with normal tyre pressure, is approximately the same as the present standard 33 X 5. The pressures we are running these tyres with is 25 lbs. It is a remarkable fact that the complete wheels fitted with these bigger tyres come out considerably less in weight than the present standard. They weigh 74 lbs. compared with 88 lbs. The tyres have straight sides but have no demountable flange and can be taken off the rims, when deflated, by hand. So far, we have only run these tyres a few hundred miles. We can appreciate they have very great advantages, but it is noticeable that they introduce other faults on the car. A further report on these tyres will follow. We will bring the car fitted with these tyres to W.W. next week. Attached is a copy of our report Hs{Lord Ernest Hives - Chair}5/LC16.5.23. with regard to these tyres. Hs.{Lord Ernest Hives - Chair} | ||