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).
Speedometer settings for car 18-EX, including tyre specifications and calculations.
| Identifier | ExFiles\Box 50\4\ Scan337 | |
| Date | 5th December 1929 | |
| X4308 5.12.29. To EFC. X.4308. RE. 18-EX SPEEDOMETER. The tyres on this car are 32 x 6.75 "Fort" Reinforced triple stud 622 r.p.m. Speedometer revs. required at 60 m.p.h. are 837 - 4% = 804 We should like this speedometer setting 4% fast. The speedometer will be required for Friday morning. Perhaps you will check the figures given above, we believe they are correct. Hs{Lord Ernest Hives - Chair}/AJL. | ||