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).
Series of recommendations on springs, damping, and tyre pressures for Phantom II and 25 HP models.
| Identifier | ExFiles\Box 16\7\ Scan243 | |
| Date | 4th May 1930 | |
| X7410 HS.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} ) FROM R.{Sir Henry Royce} DB.{Donald Bastow - Suspensions} OV. ) C. SG.{Arthur F. Sidgreaves - MD} MOT. FN. C. BV. EP.{G. Eric Platford - Chief Quality Engineer} R/W.4.5.30. X.7772 X.3806 X.7520 X.5520 X.7410 X.5410 X.235. PHANTOM II. AND 25 HP. AMERICAN & EUROPEAN ROAD SPRINGS AND DAMPING. During Hs.{Lord Ernest Hives - Chair} and E's visit to with the 1st. L H.{Arthur M. Hanbury - Head Complaints} model we discovered the front shock dampers had lost most of their oil and become ineffective due to fitting central oiling system - arrangement condemned. It shewed the great importance of ample damping especially on these bad roads and at high speed. I want therefore to impress all concerned that our recent experience confirms our recommendations of :- (1) Road springs as flexible as possible, limited only by complaints of striking the buffers, etc. (2) Ample and reliable damping which can be greater with our hydraulics than with mechanical, like Hartford's and also road springs can be more flexible if dampers effective, then be sure before fitting stiffer springs that dampers are as effective as other considerations allow. (3) It would be good to recommend that careful attention to tyre pressure is necessary according to the way the car is to be driven- i.e. a much higher tyre pressure should be used for high speed and good roads, and conversely much-reduced pressure for low speed and rough roads. This is a point often missed, and would take the place of carrying both springs and dampers, which is not possible at present. (4) Double dampers, hydraulic and mechanical, are agreed to be useful for speed models and very fast drivers. At present I fear we shall be parting from our luxury carriage practice if we fit stiffer springs (only recommended in very exceptional cases after doing all possible to dampers). Central lubrication of springs will probably permit of more effective dampers, and naturally should give more consistent results. Probably spring friction has persuaded us into using less effective dampers than are now necessary. R.{Sir Henry Royce} | ||