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).
Technical memorandum discussing issues with the front springing of the Phantom model compared to the Silver Ghost standard.
| Identifier | ExFiles\Box 67a\1\ scan0122 | |
| Date | 11th April 1926 | |
| To DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} LE CANADELHenry Royce's French residence. c. to BJ. RG.{Mr Rowledge} OY. CWB. c. to E.{Mr Elliott - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} PN.{Mr Northey} Y8410 R2/M11.4.26. RE. PHANTOM SPRINGING. X.8410 X.235 Mr. Olley says Phantom front springing is considerably stiffer than original Silver Ghost standard, but I believe his reasons are not quite correct. 1st. All spring deflections are usually checked in place under working conditions, therefore the longer axle pad effect should have been eliminated. 2nd. The front shackle leaning forward should tend to increase the deflection until one gets negative camber, but even then soon after camber (negative) occurs the shackle becomes upright and neutral. While the spring is flat the inclination of the shackles has no effect. What I fear is that we have been sending cars with springs too stiff for the load. This was agreed I think with reference to the rear and corrected. We agree that any increase in damping friction either in the springs and in the shock dampers will affect the slow speed riding, and to a less extent any increased stiffness will behave similarly. But I believe that other things being equal it would be very difficult to appreciate the difference of 12½% or one eighth in the change of deflection in the front springs while riding in the back seats. Make any kind of diagram, the change in the movements would be extremely small. Unless the following plays an important part - If the centre of gravity is halfway between the wheels any sudden lift of the front will depress the back, and at a suitable speed the natural period may be such that this motion is increased by the back wheels so that a natural pitch will receive an impulse from a single object from both axles. One thinks that good hydraulic shock dampers should help considerably, and to push the centre of gravity back may do much. This is what I set Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} to do, and will still further be possible by lighter engine. It may be found that cars with the heavier bodies are not so bad, and that the worst offenders are the light bodies on the long chassis. contd :- | ||