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).
Wheel centrepoint testing and modifications to steering and suspension components.
| Identifier | ExFiles\Box 68\1\ scan0074 | |
| Date | 24th July 1928 | |
| To OY. from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X8430 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}4/LG24.7.28. X8450 With reference to your OY4/H7.12.28. When you are testing with wheels 1/4" further out of centrepoint we would like to point out that it is almost impossible to form an opinion on a single example of any steering. We ourselves are only convinced of the slight improvement made by the 1/4" further out of centrepoint because we have also tried wheels up to 2" further out of centrepoint when the results are greatly emphasised and there is no possibility of them being masked by the characteristics of a particular car. Sets of wheels, in our experience, vary appreciably - some run out of truth more than others. The gist of this is, we should like you to try your 1/4" out of centrepoint wheels on as many cars as you can before you form an opinion. In connection with side steering tube springs. If you can now run with 3000 lbs/1" rating we cannot see any object in your going to the 1500 lbs/1" rating. I would suggest that you select an intermediate poundage. The alteration we make so that we can run with stiff side steering tube springs is to increasing the upward load on the front shock absorbers. We do this by blocking up one low pressure passage in the piston completely and in the end of the other we insert a restriction 1/4" long having a .125" hole in it. With this upward load we can employ stiff side steering tube springs and a backward pivot lean of 3° to 4°. contd :- | ||