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).
Required specifications for a hypoid gear on the back axle of the Phantom II Sports Car.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan226 | |
| Date | 26th October 1929 | |
| DA.{Bernard Day - Chassis Design} FROM R.{Sir Henry Royce} Copy to SG.{Arthur F. Sidgreaves - MD} " BT.{Capt. J. S. Burt - Engineer} " HS.{Lord Ernest Hives - Chair} PHANTOM II. SPORTS CAR. ORIGINAL [Stamp] R1/M26.10.29. X7770 [Handwritten] X2066 [Handwritten] X7350 [Handwritten] It is decided that a hypoid will be required for the back axle. One hundred miles an hour should be obtained at 3250 RPM.. 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 [Handwritten insertion] to those we know have given satisfaction. R.{Sir Henry Royce} | ||