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 effects of a low front end on chassis 3.AZ.140.
| Identifier | ExFiles\Box 146\1\ scan0036 | |
| Date | 14th October 1937 | |
| W/P. To Sr/VA. from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. Hd.{Mr Hayward/Mr Huddy} + 1245 Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}5/MH.{M. Huckerby}14.10.37. RE CHASSIS 3.AZ.140. We thank you for your Sr/VA.3/GM.7.10.37, concerning steering of the above chassis. In theory the effect on the Ph.III steering of the car being low at the front is as follows. (1) Caster angle is reduced. This should reduce directional stability and tendency to low speed wobble. (2) Rate of change of wheel camber with vertical movement of wheel is slightly increased. This should slightly increase joggles. (3) Reduced bump buffer clearance limits height to which wheels can bounce. This should reduce joggles on bad roads. In practice our experience has been that effect (1) has led to less low speed wobbling although the reduction in directional stability is not very marked. All experimental cars which have been low at the front have joggled less than standard cars. This we have attributed to effect (3) outweighing effect (2). We know that, if either or both front dampers are not working correctly, joggles are very bad. Is it possible that this was the cause on 3.AZ.140 ? Perhaps some of the grit which you noticed in the n/s housing had found its way into one of the damper valves, and was removed when you changed the springs. We should be glad to hear whether you noticed any difference in the ride which could be attributed to dampers before and after changing the springs, also whether you can check up your results on another car. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||