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).
Phantom suspension tests, specifically regarding the front springs and their effect on ride quality.
| Identifier | ExFiles\Box 67a\1\ scan0158 | |
| Date | 23th April 1926 | |
| ✓8410 To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. RG.{Mr Rowledge} c. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} c. to Na.{Mr Nadin} EP{G. Eric Platford - Chief Quality Engineer} PHANTOM SUSPENSION. We believe that we have now established the relative value of most of the features of the car with regard to the present springing complaints. The attached results are the mean of a large number of tests. The facts that have been established are :- TEST 1 In this test we have weakened the front springs by 17½%, fitted the narrow axle pads which OY. says are worth 7½% in reducing the effective spring rating, and removed the internal spring friction by means of ball races between the leaves. In other words the springs were made 25% weaker than standard with no internal friction. We compared the car in this condition with the same car in a standard condition i.e. strong front springs and front wheel brake axle. It will be observed that the difference in riding qualities measured on the rear seats is actually less than can be obtained by slacking off the standard rear shock damper setting 25 lbs. or lowering the tyre pressures 5 to 10 lbs. We consider that this test effectively demonstrates that, while there is no doubt that stiffer front springs do affect the riding of the car slightly, the alteration that we have made in fitting front wheel brakes has not changed the riding qualities from good to bad. In fact the slight difference which we measure can easily be swamped by any one of the small adjustments to tyre contd :- | ||