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).
Experimental tests and recommendations for low vs. high geared axles on the 20 HP chassis.
| Identifier | ExFiles\Box 49\2\ Scan196 | |
| Date | 8th July 1924 | |
| To FN. from Hs.{Lord Ernest Hives - Chair} c. to EP.{G. Eric Platford - Chief Quality Engineer} Y4256 Hs{Lord Ernest Hives - Chair}3/LG18.7.24. 20 HP. CHASSIS - 11 or 12-TOOTH AXLES. All experimental endurance and reliability tests have been carried out on cars fitted with the low geared axles. All our cars and R's car are fitted with the low geared axle. We consider the 20 HP. will be perfectly reliable with the low geared axle. The variation in consumption between the low geared and high geared axle will be more than swamped by the variations in conditions of running, but given the same conditions of running, the high geared axle will be 6 to 8% better. As regards speed. There will be nothing in it. The car will be quieter at similar road speeds on the high geared axle compared with the low geared. Our recommendations will be that you certainly retain the low geared axle on the Open Trials Demonstration Cars, and that the standard axle for the 20 HP. should be the low geared. The high geared axles could be fitted on exceptionally light cars or where customers ask for them. Hs.{Lord Ernest Hives - Chair} | ||