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).
Recommended tyre pressures for 40/50 HP and 20 HP models.
| Identifier | ExFiles\Box 39\2\ Scan198 | |
| Date | 3rd November 1928 | |
| Y3538 To Hm{Capt. W. Hallam - Head Repairs}: from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to EP.{G. Eric Platford - Chief Quality Engineer} BY/NW.{N. Walker - Patents} Hs{Lord Ernest Hives - Chair}/RnL/LG3.11.28. TYRE PRESSURES. ---------------- For riding comfort it is essential that the tyre pressures are as low as possible at the rear. The front tyre pressures cannot be so low because of steering wobbles. The pressures that we recommend for all cars, open and closed, are :- 40/50 HP. 40 lbs. front. } 6.75" tyre. 35 lbs. rear. 20 HP. 35 lbs. front. } 6" tyre. 30 lbs. rear. Drivers at their discretion may drop a further 5 lbs/sq.in. at the rear for town work but if very low pressures are used for touring, rapid tyre wear and loss of car control will result. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||