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).
Requirement for a hypoid gear on the Phantom II Sports Car, including specifications and design considerations.
| Identifier | ExFiles\Box 65a\3\ scan0154 | |
| Date | 26th October 1929 | |
| X7770 DA.{Bernard Day - Chassis Design} From R.{Sir Henry Royce} c. to Sg.{Arthur F. Sidgreaves - MD} By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} R.1/M26.10.29. PHANTOM II SPORTS CAR. X.7770 X.2066 X.7350 It is decided that a hypoid will be required for the back axle. One hundred miles an hour should be obtained at 3250 R.P.M. The tyres will be on 20" rims. We suggested a slightly higher gear until the engine peaked at a higher speed, but Hs.{Lord Ernest Hives - Chair} thinks that this gear will be high enough. It was suggested that this would be the 13/41., but I think the calculations should be checked. Apparently there is no gear in existence. I think the diameter of the bevel pinion should be increased in proportion, and the angles kept very near to those we know have given satisfaction. R.{Sir Henry Royce} | ||