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 calculations and adjustments for the 20/25 chassis.
| Identifier | ExFiles\Box 165\4\ img201 | |
| Date | 11th July 1933 | |
| x1807 By/CGH.{W Clough} From Hs{Lord Ernest Hives - Chair}/Wst. Hs{Lord Ernest Hives - Chair}/Wst.7/MA.11.7.33. 20/25 CHASSIS SPEEDOMETERS. Referring to your By/CGH.{W Clough}1/G.11.7.33., our calculations for the 20/25 chassis with 11/50 axle, 19" roadwheels and Dunlop tyres shew the speedometer revs per mile to be 838. We agree therefore that standard speedometers should be immediately altered to 840 revs per mile with necessary scale adjustments to make the speed reading 5% fast at full scale. Hs{Lord Ernest Hives - Chair}/Wst. | ||