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).
The gear ratio and other calculations for a speedometer drive on a gearbox.
| Identifier | ExFiles\Box 50\4\ Scan032 | |
| Date | 4th December 1922 | |
| X4308 Mr. Hives from GWH. {George W. Hancock - Head Chateauroux} 4.12.22. 49-GB. GEAR RATIO OF SPEEDOMETER DRIVE ON GEAR BOX 35/4 to 1 engine. Axle ratio 15/52 = 3.46 to 1. 20 m.p.h. Engine revs. 711.3 20 m.p.h. Road wheels 33 X 5 205.57 r.p.m. 20 m.p.h. Speedometer revs. 251.825 p.m. Direction of speedometer drive - clock-wise. Turns per mile of speedometer drive = 737.08. -(Hs {Lord Ernest Hives - Chair} /Rn {Mr Robinson} ) GWH. {George W. Hancock - Head Chateauroux} | ||