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 discussing spring suspension and the re-distribution of weight in motor cars.
| Identifier | ExFiles\Box 43\2\ Scan148 | |
| Date | 4th May 1926 | |
| Oy1-E-5426 May 4th, 1926. To: Mr. Basil Johnson, Rolls-Royce, Ltd., London, England. (Copy for attention of Mr.F.H.Royce " " " " Mr.Day " " " " Mr.Elliott " " " " Mr.Bailey) Dear Sir: Re Spring Suspension Re-distribution of weight We notice some reference in recent experimental reports to redistribution of the masses of the car. We think perhaps the following notes may be of some use, or that we may receive a reply which will help us to establish what we have in mind, namely the moment of inertia of different body types about a horizontal transverse axis through the C.G. I. We read some time ago in H.S.Rowell's paper of March 1923 before the I.A.E. that a condition was desirable such that k2 = axb. Where "a" and "b" are the portions of the wheelbase, either side of the C.G. This condition would cause the spring suspension one end to be independent of the suspension at the other. It was equivalent to each axle being the centre of percussion for the car when the other axle is considered as the centre of suspension. (a) The Chrysler 4 cylinder engine is suspended on this principle, to minimize the reactions of the harmonics on the frame. (b) In a recent ride in a Packard 8, with custom-built sedan body, it appeared to us that accidentally, this condition may have been approached, because, though the front end did not ride well, the rear seat, directly over the rear axle, was not unduly affected by the movement in front, and was therefore comfortable. | ||