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).
Letter detailing test results on front springs, specifically the effect of the wide axle pad and front shackle inclination.
| Identifier | ExFiles\Box 43\2\ Scan119 | |
| Date | 5th April 1928 | |
| Oy2-E-4526 BJ M.H 18 APR REC'D April 5th, 1928 POST 16 APR RECEIVED Mr. Claude Johnson, Rolls-Royce, Ltd., London, England. (Copy for attention of Mr.F.H.Royce " " " " Works Committee " " " " Mr.Beaver " " " " Mr.Hedin (England) " " " " Mr.Burton) Dear Sir: Re: Front Springs In connection with the riding of cars with front brakes we have made some tests to determine the effect on the front spring of (a) The wide axle pad used with front brakes, (b) The inclination of the front shackle. (1) First of all we should point out that our tests were made on front springs of Phantom type, 43-1/2" long, but having our present standard free camber of 3-1/2". The Phantom springs are initially 13% stiffer than our present standard as they have only 3.1" deflection to normal loaded position, as against 3.5" deflection on the older type. (2) a.{Mr Adams} Taking the range of deflection from flat to 1" negative we find that the wide axle pad with the clips tightened down as compared with a support on the spring 2-1/2" wide (which we use for normal spring testing) stiffens the spring 7-1/2%. In the second inch of deflection there is a greater stiffening effect. With the narrower axle pad used without front brakes we find little stiffening effect. | ||