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).
Experiment to improve the springing and ride comfort on Phantom I chassis 110-DC.
| Identifier | ExFiles\Box 18\3\ Scan233 | |
| Date | 30th April 1931 | |
| To R.{Sir Henry Royce} From Ha/Lid.{A. J. Lidsey} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to R.{Sir Henry Royce} Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} Hd.{Mr Hayward/Mr Huddy} PHANTOM I. SPRINGING. X.8410. X.7960. On chassis No. 110-DC, we have fitted road springs having greater deflection for load than standard P.I springs. The experiment is conducted on the same lines as were followed on P.II cars for U.S.A. The front springs fitted have 35% greater deflection, and the rear 30% greater deflection than standard, the front hydraulic dampers have been altered to 120/120 lbs. and the rear to 80/100 lbs, the high pressure valves being drilled .032" dia. on all dampers. This damper load is the same as is used on American P.I. cars and gives the softest ride. The springing on this car is greatly improved due to these modifications, and when tried against a standard P.I. car gives a considerably more comfortable ride than the standard car. The springing is very much softer and the characteristic short sharp pitching between 20 and 25 mph. is very much reduced. Riding over really rough roads is more comfortable and at the higher speeds the usual "throwing" and harsh riding is considerably improved. It may be criticised from the point of view of being too flexible at the rear; this we think will become automatically corrected with use, the springs are new and very well lubricated, and when their internal friction increases as it will do when the lubrication becomes less effective, the flexibility will be slightly reduced. We have put this car up to the Repair Dept as a possible solution to some of their P.I. complaints of hard riding. The results we have obtained on this car are not as good as those obtained on the Phantom I. car S.404.MR which was over here with Cy. last year, in spite of the fact that the damper loadings are the same, and the rear spring deflection almost identical, also on 110-DC, the front spring deflection is actually greater than on the American car. The difference in results may be due to inter-leaf spring friction. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} | ||