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).
Squeal tests for three categories of Avon tyres.
| Identifier | ExFiles\Box 156\3\ scan0274 | |
| Date | 16th December 1941 | |
| 1331 Car 3010 (b) 3010 To Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} c.c. Rm{William Robotham - Chief Engineer}/RJH. Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager}11/OH.16.12.41. AVON TYRES. Herewith report on special tyres supplied by Avon India Rubber Co, the tyres submitted to us for test were in 3 categories 1. Avon Special Speed Tyres (five-bar centre traction pattern) 2. Avon Standard Silent Tyres with 1" radii at tread edges. 3. Avon Standard Silent Tyres with special tread compound. We are unable to distinguish any difference between any of these tyres. From a squeal point of view, as they all squeal at 15 - 16 M.P.H. Herewith Table:- Squeal Standard LC.7466 - LC.7404 - LD.1987 - LD.1979 15 - 16 Speed Tyres five - bar pattern. LH.{Mr Haworth}3530 - LH.{Mr Haworth}5022 - LH.{Mr Haworth}5070 - LH.{Mr Haworth}5081 15 - 16 Silent Tyres 1" radii tread edge 15 - 16 Silent Tyres Special tread compound LH.{Mr Haworth}4656 - LH.{Mr Haworth}4654 - LH.{Mr Haworth}4603 - LH.{Mr Haworth}3538 15 - 16 Pressures used on all tests:- Front 25lbs. Rear 28lbs. Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} | ||