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).
Letter from Avon India Rubber Co. Ltd. requesting details on tyre testing methodologies for slip angles and sideways acceleration.
| Identifier | ExFiles\Box 156\3\ scan0051 | |
| Date | 27th April 1938 | |
| 1331 MANUFACTURERS OF AVON TYRES, SPORTS SUNDRIES, FOOTWEAR, FLOORING & MECHANICAL RUBBERS Telegrams RUBBER MELKSHAM Telephones MELKSHAM 120 (6 LINES) Established 1885 The AVON INDIA RUBBER Co LTD. SYMBOLS OF ENDURANCE Chairman MAJOR R.F. FULLER, J.P. Deputy Chmn. SIR HERBERT E.{Mr Elliott - Chief Engineer} BLAIN C.B.E. M.INST.T. Secretary & Accountant, E.H. LOVELL, F.C.I.S. Service Depots. LONDON BIRMINGHAM, BRISTOL, MANCHESTER GLASGOW, LIVERPOOL, BELFAST NEWCASTLE, DUBLIN, NOTTINGHAM Our Ref. JGM/AP Your Ref. ________ Regd. Office & Works MELKSHAM, WILTS. 27th April 1938 Othg/Repl (Rm{William Robotham - Chief Engineer}) F.H. Messrs. Rolls-Royce Ltd., DERBY. Dear Sirs, For the attention of Mr. F.J. Harding. We thank you for your letter of April 20th to which were attached copies of the results of your tests on the various tyres we sent to you recently. We would like to learn what formula you use for calculating the slip angles from the average telescope readings. We are also in some doubt as to your method of obtaining the various values of sideways acceleration which are used in plotting the curves. Are we correct in presuming that, from the values of sideways acceleration which were obtained with your special barometer when the Fisk tyres were fitted to the car, at various speeds you plotted a curve relating speed to sideways acceleration, and that from this curve you read off values of sideways acceleration for all the other speeds used in the various tests? We are interested to learn that the 6.50/16 India tyre was of 6 ply construction. By analogy from the results of the Avon 6 and 4 ply 6.50/17 tyres I take it we can assume that an Avon 6.50/16 6 ply Duotread tyre would have compared more favourably with the India 6.50/16 6 ply tyre than did the Avon 6.50/16 4 ply Duotread tyre used in these tests. -1- | ||