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).
From Detroit discussing tyre noise and the use of rubber isolation in rear springs, with diagrams.
| Identifier | ExFiles\Box 173\4\ img119 | |
| Date | 23th November 1935 | |
| COPY (Memo. from Da.{Bernard Day - Chassis Design}) DETROIT. 23. November, 1935. To E.{Mr Elliott - Chief Engineer} from La.{L. A. Archer} Tyre Noise. We have had some confirmation of the view that the rubber isolation at the rear has something to do with eliminating tyre noise. Cadillacs frequently have noisy tyres, but 90% they say, comes from the front. They put one car on the drums, with very noisy front tyres, plain tyres on either end were quite quiet. The same noisy tyres at the rear were very much quieter than in front. The front suspension in this case had no rubber except a pad .625 thick under the lower end of the spring. The rear end was fully insulated. I have a sample of the rubber in the centre of the rear springs, thus:- RUBBER .25" THICK SHEET STEEL SHEATH .040 THICK RUBBER .0625 THICK The rubber and sheet steel sheathes extend right under the holding down bolts, which latter are pulled up as tight as they can be. The rubber is also carried round the spring centre bolt both top and bottom. The Cadillac people claim that it does not interfere with steering or the axle control under torque, and braking. STEEL SHEATH RUBBER STEEL SHEATH | ||