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).
Vehicle ride quality complaints, comparing different tyre pressures and suspension setups.
| Identifier | WestWitteringFiles\O\January1926-March1926\ Scan169 | |
| Date | 11th May 1928 | |
| (2) (6) By fitting balloon tyres (20/25 lbs. per sq. in.) the riding of the car was generally improved, but the complained of feature was still definitely there. (7) Fitting high pressure tyres at 80 lbs. per sq. in. made this particular feature no worse, but if anything rather less noticeable, probably due to the distraction caused by the high speed vibrations now set up. (8) In a 20HP. car with standard springing and shock dampers the complaint was so little noticeable as to be negligible. This was as far as the main demonstration was able to go, but subsequently Mr. Hives, Mr. Hardy, and myself agreed as a result of further demonstration that:- (9) A Works service landaulet, one of the first cantilever sprung cars, built with of course front springs of the original flexibility (3½" initial deflection) and no rear shock dampers, had the complaint, though not quite so noticeable as the trials landaulet of (1). (10) The trouble is not confined to RR. cars. The Hispano is very bad, and an Austin car which happened to be there for demonstrating pneumatic cushions, also had the complaint to some extent. In the above report we are dealing with this particular feature only, and do not question the improvement in the general riding which will be produced by the use of very flexible back springs and low pressure tyres. The impressions left on us from these tests is that as regards this jolting feature the difference between a Silver Ghost of 'U' series and a New PhantomCodename for PHANTOM I is not really distinguishable, and a pre-'U' series Silver Ghost is only a little better. DA.{Bernard Day - Chassis Design} [STAMPED TEXT: RECEIVED 11 MAY 1928] | ||