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).
Modifications to a 20/25 chassis by fitting smaller wheels to achieve a low gear ratio effect.
| Identifier | ExFiles\Box 106\4\ scan0146 | |
| Date | 15th February 1935 | |
| +5810 To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c.c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} re 20/25 fitted with smaller wheels to give low gear ratio effect. Referring to the above proposal, we should like you to fit up a chassis with the smaller road wheels and the existing third crossmember unaltered, and test the car in this condition. We are of the opinion that the transmission shaft will never touch the crossmember as we can only make it foul .375" under extreme theoretical conditions and from our experiences on the Bentley with the exhaust pipe under the axle we do not believe these conditions are ever reached on the road. It is very desirable to avoid turning the crossmember round to avoid adding a lot of weight to the chassis which would be required for extra bracket facings in carrying the silencer, two sets of brake levers and two attachments for the battery box from the hollow side of the crossmember, as well as the question of making a lot of chassis changes. Failing the above being satisfactory we propose to increase the depth of the crossmember and make some small sacrifice of road clearance on full bump mounting to not more than 1/2", which would still leave the 20/25 chassis better off then the Phantom in this respect, and which would avoid reversing the crossmember. E.{Mr Elliott - Chief Engineer} | ||