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 of Phantom II rear springing and rear axle movement under various road conditions with different dampers.
| Identifier | ExFiles\Box 182\M19\ img155 | |
| Date | 20th April 1931 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} c. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} c. to Da.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} ORIGINAL: Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}6/KT. 20.4.31. x7520 x7350 P.II REAR SPRINGING. REAR AXLE MOVEMENT. We have carried out a series of tests to ascertain the maximum rebound movement of the P.II rear axle under two road conditions, driving over a railway crossing and also over a very bad hump backed bridge at various speeds. The tests were carried out using R.R. hydraulic dampers with and without drilled valves, and also using Delco Lovejoy dampers (with adjustable leak) with the maximum and minimum leak provided. The results obtained shew a maximum recorded rear axle rebound of 7.6", the equivalent bump being 5.75" (13.35" total axle movement), when using R.R. dampers with drilled valves; this is the softest ride we know at present. The reverse condition, using Delco Lovejoy dampers with the minimum leak provided (which gives a sports car type of suspension) records a maximum rebound of 6.7" with equivalent bump of 5.5" (total movement 12.2"). There is therefore only a relatively small difference; 1.1" axle movement, between the two contrasting types of springing, very soft ride and sports car springing. It is not possible to control the rear axle rebound movement within smaller limits than this by shock absorber loading and at the same time secure a reasonably good ride. It appears therefore that any new shock dampers should be arranged with levers to accomodate the maximum recorded axle movement. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} | ||