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).
Comparison of American and English car springing, advocating for ample damping for safety on varied road conditions.
| Identifier | WestWitteringFiles\U\2January1930-September1930\ Scan195 | |
| Date | 2nd July 1930 | |
| SG.{Arthur F. Sidgreaves - MD} & HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} C. to OY. or D.F.C. C. to PN.{Mr Northey} CAR SPRINGING. AMERICAN & ENGLISH COMPARED. X8410. X7410. X5900. Replying to SG{Arthur F. Sidgreaves - MD}17/E1730., with reference to the superiority of the American cars over those in England (English P.l. and American P.l) in springing, in all the specimens we have seen the American car has greater average flexibility of springs, less friction, and less damping, than the English equivalent. (there is no mystery,) and because of this it is better for most good roads at moderate speeds, and probably quite good on very good roads at high speeds, but it has been proved that on secondgrade roads such as we get in Sussex, and on narrow cambered roads such as at Newmarket, such a car is dangerous at high speed, and we cannot for a moment agree to turn our standard car out in the same condition as the car which OY. was so keen to demonstrate - i.e. ineffectively damped.) In America the roads are wider, and therefore would naturally have relatively less camber, as well as being less undulating, especially at the edges, (when compared with our English and many continental roads.) We must also bear in mind that the easiest way to get a car to run comfortably is to let down the tyre pressure, which can do a great deal more than we can do with the springing and damping. Recent reports have proved that the American P.l. was dangerous on Brooklands even at its maximum speed of about 10 MPH. slower than the English P. 2. Everyone should understand that I can only agree to our practice being - (1) springs being as flexible as possible to the limits of an absence of frequent bumping, (2) ample damping to make the car safe at the speed it is likely to run; when tested on secondclass roads ample damping enables more flexible springs to be used with equal safety and freedom from bumping. We have long advocated this policy, but it is difficult to get every car correctly sprung because of the various weights and errors of judgment. 18-EX. has been an excellent model. There are very few complaints when cars are so turned out unless the tyres are run unnecessarily hard, which can spoil any effort of ours. Finally I do not agree to drilling shock damper valves because it is no use for the quick movements of the axle where it might be beneficial, and renders the dampers nearly useless for the slow body movements which we wish to steady, for safety, and to avoid seasickness. R.{Sir Henry Royce} | ||