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).
Comparing the diameters of Dunlop straight-sided and beaded tyres and the negligible effect on the gear ratio.
| Identifier | ExFiles\Box 45\1\ Scan251 | |
| Date | 27th January 1922 | |
| X4050 C. from Hs.{Lord Ernest Hives - Chair} c. to BY.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} Hs{Lord Ernest Hives - Chair}2/LG27.1.22. DUNLOP STRAIGHT-SIDED TYRES. X4050 X4299 At your request we have measured the difference in diameter between a 895 X 130 Dunlop cord beaded tyre and a 33 X 5 Dunlop straight-sided tyre. We find that the Dunlop beaded tyre measures 34 3/8 dia. - the straight sided tyre in a similar condition measures 34 5/8 dia. This slight difference in diameter would be negligible on the gear ratio. It would be swallowed up by the differences in tyre pressure or the wear of the tyres. Hs.{Lord Ernest Hives - Chair} | ||