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).
Optimal gearbox and back axle ratios for cars.
| Identifier | ExFiles\Box 6\4\ 04-page191 | |
| Date | 21th September 1928 | |
| BJ. OY. Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to Wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} V5310 R2/M21.9.28 RE. GEARBOX AND BACK AXLE RATIOS. X.5310 X.5350 X.2061 Firstly, I agree that 14-tooth axles are better for all cars for everyday use, because only very few expert drivers will change down when good acceleration is needed, (but it suggests even lower gears for heavy cars.) Secondly, I am not in favour of any of the unorthodox gearboxes I have so far seen, including the Ahlen. I doubt also the lasting qualities. Perhaps this matter will be attacked by supercharging the engine. Anyway, it still seems to me better to concentrate on the engine, and as we get engines more perfect, there seems less objection to a low top gear. We have done something towards this lately in a stiffer crankshaft, rubber mounting, max. HP. at higher speed. The 20 HP. top gear on 12-G-4 is I believe the best ratio we know at present. R.{Sir Henry Royce} | ||