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).
Analysis of springing on a 20/25 HP model, discussing weight distribution and ride quality.
| Identifier | ExFiles\Box 106\1\ scan0367 | |
| Date | 17th September 1935 | |
| x546 Spare Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} BY.8/N.17.9.35. Re: 20/25 HP. SPRINGING. Reverting again to the above subject, and dealing particularly with the information which you conveyed to me under cover of Sg{Arthur F. Sidgreaves - MD}7/E.9.9.35, I think the facts of the case can now be conclusively dealt with :- (1) I expressed the opinion in BY.1/G.5.9.35, that it was difficult to accept the idea that the fitting of a set of springs which were over-loaded to the extent of 1 1/2 cwts, could account for the improvement in the riding. The distribution of this weight would be 21 lbs on each front spring light, and 63 lbs on each rear. The actual spring poundages being 850 lbs on the front offside and 800 lbs nearside, and 1100 lbs on each rear. The 21 lbs would represent as a percentage 2 1/2% light in weight on the front and 5% on the rear, and I think expressing it in this way, it would be clear these differences are negligible, in fact I do not think the most fastidious person could detect so small a difference in the car springing. (2) To what then is good riding attributed. We of course admit without question your description of phenomena viz. that the riding is good front and rear, but we consider that there is a good reason for this in as much as: (a) the car is a close coupled saloon where the passenger sits well forward of the rear axle. (b) although the car is continental type, its total weight is high ( 40 1/2 cwts). This means firstly that the car is of a type that is inherently good for riding in the rear seat, owing to the position of the rear seat, and secondly it is always agreed that the heavier body of a type also rides better than a light body of a similar type. Cont'd.{John DeLooze - Company Secretary} | ||