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).
Decision to use a three-speed gearbox on the American model chassis.
| Identifier | ExFiles\Box 137\5\ scan0012 | |
| Date | 17th November 1919 | |
| X 9720 To DA.{Bernard Day - Chassis Design} from R.{Sir Henry Royce} Copy to CJ. " " WOR.{Arthur Wormald - General Works Manager} " " BN.{W.O. Bentley / Mr Barrington} " " EH. R6/G17.11.19. X.3720. X.3614. X.3706. RE AMERICAN MODEL CHASSIS. You will understand that it has been decided lately that the American model chassis will be an ordinary right hand one but with three speed box and central change speed levers. The reason for this 3 speed departure is (a) to facilitate the manufacture of the gear box, (b) the fitting up of the change speed control levers, (c) and to enable an ordinary type starter to be fitted to the flywheel, relieving Derby of the necessity of making our special type of starter in such large nimbers as to supply the American factory. I hope from the drawings we have sent you of the new three speed gear box you will be able to make good progress with the chassis for the American model. You will see that we have proposed to fit the cross member immediately behind the gear box 1 1/2" further forward. This will have the advantage of giving a little longer torque rod. It has a slight disadvantage in the bolting of the canti-lever pin which carries the front end of the rear spring, as we cannot very well alter the length of the spring. It will be observed that this same disadvantage will occur with the extra long chassis, but I do not think the load at this point is sufficient to cause us any anxiety. R.{Sir Henry Royce} | ||