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).
Procedures and limits for testing tyres for 'out of truth'.
| Identifier | ExFiles\Box 4\3\ 03-page45 | |
| Date | 7th October 1925 | |
| BY.{R.W. Bailey - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} c. BJ. 4401 EP{G. Eric Platford - Chief Quality Engineer}8/H7.10.25. re. Out of Truth of Tyres. With reference to BJ's memo BJ19/H30.9.25. the last paragraph - will you please issue technical instructions to the Works, and let us have a copy, giving particulars as to the test to be carried out, to ascertain that tyres are in truth or not, and the limits to which they are to work. In discussing this matter with the Experimental Dept. it does not seem to be sufficient to jack the wheels up and test the tyres for truth in this manner, but it is a question, if possible, of arranging for some scheme of testing them under load. EP.{G. Eric Platford - Chief Quality Engineer} P.S. Since writing the above we have seen Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG6.10.25 We assume from this that in regard to customers' tyres fitted on cars at the Works that it is only possible to test these for out of truth by spinning the wheel complete with tyre on its hub, and rejecting those which are out of truth, as per the last paragraph of Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG6.10.25. Can we be informed please, to what limits we should work in testing tyres under these conditions for being out of truth. It will of course be understood that we do not run customers' tyres for a greater mileage than we can possibly help at the Works, and it would not seem practicable to take any such out of truth tests as suggested in the third paragraph of Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG6.10.25. EP.{G. Eric Platford - Chief Quality Engineer} Surely EP{G. Eric Platford - Chief Quality Engineer} would be the one to find out at once just what these limits were, having in mind a) counsels of perfection & b) realistic lots etc which the tyre m/f/rs{Sir Henry Royce's Secretary} can be persuaded to aim | ||