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 performance and gear ratios of a 4-speed gearbox with a right-hand change fitted to a 20 HP car.
| Identifier | ExFiles\Box 75\1\ scan0303 | |
| Date | 12th December 1924 | |
| Y4247 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c.c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}5/LG11.12.24. 4-SPEED BOX WITH RIGHT-HAND CHANGE X5310 FOR 20 HP. We have one of these boxes fitted on a 20 HP. car. The box has been built up without the servo drive. The silence of the gears is quite satisfactory. There is a slight noise from the continuous gears. We attach herewith a chart which shews the comparative gear ratios. It will be seen that the 3rd. speed on the 4-speed box is very close to the 2nd. speed on the present 3-speed box so rhat under ordinary average conditions in a district where one uses the top and 2nd. speed, there is no noticeable advantage. There is an appreciable advantage when it comes to a hill which demands the 1st. speed on the present gear. The car fitted with this box has been sent to WW. for R.{Sir Henry Royce} to examine. Hs.{Lord Ernest Hives - Chair} | ||