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).
Springing and shock absorber setup for the Phantom II chassis based on extensive road tests.
| Identifier | ExFiles\Box 16\7\ Scan206 | |
| Date | 21th November 1929 | |
| X.7410. To Ps. from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. EP.{G. Eric Platford - Chief Quality Engineer} c. FN. Hs{Lord Ernest Hives - Chair}/Rml/AD21.11.29. SPRINGING OF PHANTOM II CHASSIS With reference to Psl/RJ18.11.29. As you are probably aware we have been working continuously on suspension for the past two years. While the three 10,000 mile tests were being run in France on Phantom II, several weeks were given up to finding the best shock absorber loading for all round conditions. These tests were actually carried out on the French roads as we always feel that any modifications we make to suspension for slow speed riding must be capable of allowing the car to be driven at maximum speeds on Continental roads. Phantom II cars are fitted with the loadings we decided upon as a result of our tests. We are sure that if you reduce these loadings very much the passengers will hit the roof when going over bad strips of road at speed far harder than they ever did on Phantom I because we now have lubricated spring leaves. You will remember that this was the complaint you demonstrated to us down by the river on more than one occasion as being of vital importance. We would therefore suggest that you bear this in mind when you make any alteration. Both shock absorber valves are now adjustable externally, and we send you a sheet shewing how these adjustments may be carried out. We must point out however, that (1) You will always find that the light Weymann sports type of car will be most difficult to spring unless it is of the 18-EX type i.e. two spare wheels behind, with the passenger sitting well forward of the rear axle. If it is not of this type, you will never be able to spring it as well as the maximum body Hooper type car. (2) It is no use making the upward load on the shock absorber very much less than the downward loading with the present Phantom II shock absorbers. If you do this you will get a violent pitching at speeds over 40 miles an hour which will be quite intolerable. | ||