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 characteristics and customer benefits of the PH.III steering system introduced on the 'Wraith' E series.
| Identifier | ExFiles\Box 95\1\ scan0506 | |
| Date | 18th October 1938 | |
| 350 W/S. To Cx.{Major Len W. Cox - Advertising Manager} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}6/MH.{M. Huckerby}18.10.38. PH.III STEERING. Re your memo Cx.{Major Len W. Cox - Advertising Manager}7/KW.12.10.38, the characteristics of "Wraith" wheel movement which is to be introduced on E series are that the change of camber of the front wheels and the change of castor angle are both reduced during vertical movement of the suspension. The benefits of these to the customer are as follows:- (1) The reduced change of camber almost entirely eliminates the joggle on rough roads which now occurs at speeds above 30 m.p.h. (2) The steering is more stable directionally during heavy braking as the decrease of castor angle when the front of the car dips is less. (3) The more constant castor angle allows the angle to be reduced in the normal position so making the steering slightly lighter and reducing the liability to low speed wobble. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||