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).
Tests carried out on the springing of the Phantom II model.
| Identifier | ExFiles\Box 182\M19\ img112 | |
| Date | 7th February 1931 | |
| ORIGINAL To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} c. to Sg.{Arthur F. Sidgreaves - MD} Hor. c. to Da.{Bernard Day - Chassis Design} Ey. c. to EF. Hd.{Mr Hayward/Mr Huddy} c. to GsH. Hs.{Lord Ernest Hives - Chair}1/KT.7.2.31. x7410. PHANTOM II SPRINGING. Further tests have been carried out on various P.II cars using lower rating front and rear road springs than the present standard. These tests have been limited to a consid-erable extent by the fact that for a period, only one pair of front springs was available for test. These were a pair of 1125 lbs. springs with an initial camber of 5.4" and were the pair originally fitted to Sg{Arthur F. Sidgreaves - MD}'s car, 58-GN, and eventually taken off owing to their being too strong for the car. Later, more springs were received from the manufacturers and fitted on three cars, viz, 58-GN, 18-EX, and 25-EX. A lot of work was done and results were obtained on our water spilling method of measuring riding comfort. In every case considerable improvement was registered after fitting the lower rating springs. All these results of course relate to one particular stretch of road, and give a good impression of personal comfort for it, but the method cannot be used for the normal average run over all sorts and conditions of roads. For this reason we shall not circulate the results obtained and we have decided to abandon this test and revert to recording personal impressions, we do not at the time know any better method. The big advant-age to be gained by fitting springs having greater deflection than standard for a similar load, is a reduction in pitching, as we are limited however to the extent of flexibility to which we can go by several factors. (1) Steering, which is made less selective and more inclined to joggle by the use of ultra-flexible springs not very adequately damped. (2) Rolling and swaying on heavy bodies. (3) Raising the car (the buffer clearance with low rat-ing springs must be increased to give the same freedom from hitting the buffers as exists when using the standard springs.) All these three points can be corrected by using dampers which give comparatively free spring movement for small deflections, but which will increase to a big damping load for large axle movements. Using the present standard shock dampers we can | ||