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).
Discrepancies in recommended tyre pressures and axle loads from Dunlop.
| Identifier | ExFiles\Box 39\2\ Scan153 | |
| Date | 18th July 1922 | |
| X3538 ROY.{Sir Henry Royce} c. to Wox. c. to He. c. to By.{R.W. Bailey - Chief Engineer} c. to Hm.{Capt. W. Hallam - Head Repairs} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Hr. EP{G. Eric Platford - Chief Quality Engineer}/Thn9/019.7.22. dict. 18.7.22. Re. Dunlop Tyre Pressures. -------------------- We have received your memo. ROY{Sir Henry Royce}/HRA12/FJ17.7.22. also the Booklet from the Dunlop Co. re. Care of Tyres. We have referred to Page 9 of this booklet, and although certainly Dunlop's have brought their recommendations re. pressure per sq. inch to what we recommend, i.e. 45 to 65 lbs. the loads which they recommend per axle are much less than the loads which will be made on R.R.cars. Taking the 895 x 135 Cord tyres which is the size we recommend, the recommended maximum weight per axle by Dunlops is 21. cwt. for a pressure of 45 lbs. whereas the least weight on a R.R. car rear axle is 25 cwt. Our wishes therefore are that these weights for the 895 cord tyre should be put up by at least 3 or 4 cwt. per axle. The 895 x 150 weights may be satisfactory, but as you are aware we do not recommend 895 x 150 size for our cars. We trust that something will be done to really get this matter on to a proper footing. The above remarks apply principally to rear axle weights although the axle loads for front axles should also be increased over and above the loads given by Dunlops. EP{G. Eric Platford - Chief Quality Engineer}/Thn. RECEIVED, FC JUL 20 1922 | ||