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).
Bumper test for Phantom chassis front springs, comparing performance with and without Ferodo interleaving material.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan179 | |
| Date | 1st November 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}2/LG34.11.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to RG.{Mr Rowledge}✓ E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer}✓ c. to Wor.{Arthur Wormald - General Works Manager}✓ BUMPER TEST ON FRONT SPRINGS x8772 (crossed out) ON PHANTOM CHASSIS. x8410 (crossed out) On the bumper we have tested Firths front springs with and without Ferodo interleaving material between the plates. The advantages claimed for the interleaving are :- (1) Increases damping effect on spring leaves which would mean less work for the shock absorbers. (2) The friction between the leaves would remain constant. (3) No lubrication required. We should therefore get rid of 12 lubrication points. (4) No spring squeaking. The disadvantages of the interleaving material is that the material itself is nearly .060" thick and if it is inserted between each leaf, it raises the car about .750". It also makes it more difficult to grip the spring tightly to the front axle. It may be that the advantages could be obtained by only using the interleaving under two or three of the top plates. Our experience is that it is the top plates which cause most of the squeaking. The results on the bumping test did not show any appreciable difference in the life of the springs whether Ferodo interleaving was fitted compared with the standard springs. Below is the life of the top plates :- | ||