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).
Steering improvements on the 12-EX car, focusing on hydraulic dampers, steering geometry, and the impact of tyres on wobbles.
| Identifier | ExFiles\Box 17\3\ Scan057 | |
| Date | 23th August 1926 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to PN.{Mr Northey} CWB. c. to CY. E.{Mr Elliott - Chief Engineer} X7430 Hs{Lord Ernest Hives - Chair}1/LG23.8.26. STEERING ON 12-EX CAR - R1/M20.8.26. Y235 We are satisfied that the new front axle and the hydraulic dampers fitted to the front are definite improvements compared with the present standard parts. When we changed from the 1.125" lead to the .720" lead we made a marked improvement, but we feel confident that with the new axle and perhaps modifications to the side steering tube spring arrangement, we can still further improve the steering. If we add friction to avoid low speed wobbles (we can do this with the present lower geared steerings without it being objectionable), we can then use lighter and set up springs in the side steering tube which you advocated some time ago. As regards the hydraulic dampers. These are more reliable and more consistent than the present friction type, they also reduce the tendency for high speed wobbles. The recent tests shew again that tyres are the biggest factor in starting high speed wobbles. This point is now being generally recognised because although we were criticised for expecting customers to balance wheels, this is now being done on all fast cars which have front brakes and use low pressure tyres. We have recently tested several makes of cars: we know that none of them are contd :- | ||