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 a vehicle's rear frame, suspension, and jacking system, with comparisons to a Jaguar.
| Identifier | ExFiles\Box 126\5\ scan0010 | |
| Date | 3rd July 1936 guessed | |
| (sheet 2) The frame is so low that the rear road springs have to be placed inside of, and on a level with the side-members. This decreases the distance between the springs but the body is so low that it probably does not matter. The springs are as one would expect unlubricated and without gaiters. This scheme of bringing the road springs inside the frame is one that we considered for SpectreCodename for Phantom III, and one that we intend to try out experimentally on Wraith. I am inclined to think it gives better axle control to raise the springs relative to the axle as high as possible, and the loss in anti-rolling effect can be compensated for on the roll rod. Everything on the Jaguar is naturally arranged for cheapness, for example, instead of providing forgings for locating the front ends of the rear springs there are a couple of punchings arc welded to a tubular crossmember. This arc welding always looks very rough and untidy, but apparently holds together. There appears to be no way of removing the petrol tank except by taking off the bodywork. The bodywork has to be specially designed to accommodate the movement of the rear axle above the under slung frame, and apertures are provided in the wheel arches which are apparently sufficiently large to thread the rear axle out sideways. We were naturally interested in the jacking system provided, and this appears to work quite well. One would gather however that the road springs are fairly stiff by the way the wheel comes off the ground, and these springs are of the type having a number of top leaves above the master leaf. The car as a whole also appears to be pretty rigid when jacked up at one corner. The support for the rear jacks is actually carried on the coachwork. It has a thin section running back on to the frame but of such length and flexibility that it would bend up if it were not bolted to the coachwork at the outer end. The Jaguar people areeeasily able to make this | ||