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).
Conflicting tyre pressure recommendations for Michelin Cable Tyres and their impact on ride quality.
| Identifier | ExFiles\Box 39\2\ Scan089 | |
| Date | 12th October 1921 | |
| R.R. 950a (20 T) (S.H.Scd. 24-9-20) G 2843 [Handwritten annotations start] BJ. Copy to I.H.S. Py Have not D.S. X3538 RECEIVED [stamp with clock face] Instructions been issued re tyre pressures after Derby Conference TEST DEPT. 12 OCT. 21 LE2/H/11.10.21. [Handwritten annotations end] MICHELIN CABLE TYRES --------------------- The Michelin Tyre fitters have orders from their Head-quarters to put 85 lbs pressure into tyres when fitted. We have tried cars with this pressure and find that the riding is very hard, and it is necessary for us to reduce the pressure to 60 - 65 lbs which certainly does make a slight improvement. We understand from the Michelin Tyre fitter that this is contrary to their recommendations and they consider that running at this pressure is detrimental to the tyres. We shall be glad to have your instructions on this matter as we feel that we shall have complaints from customers regarding the harsh riding of their cars with these tyres. [Signature] J.L.E. [Initial] Sp.{Mr Spinney} | ||