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).
Front spring deflection, riding comfort, and high-speed wobbles.
| Identifier | ExFiles\Box 67a\1\ scan0154 | |
| Date | 20th April 1926 guessed | |
| contd :- -5- source of complaint. While weaker front springs do not shew up to great advantage under these circumstances, our impressions from driving cars on indifferent and bad road surfaces are that in this case a 20% increase in the deflection on the front springs gives a very appreciable improvement in riding comfort. We know, however, that flexible front springs are bad for high speed wobbles quite apart from the difficulties experienced in providing for braking torque. We are carrying out a test to see if the hydraulic dampers will deal with high speed wobbles on front springs with 20% greater initial deflection than at present. (i) With reference to OY's estimate of our increase in front spring strength. As you surmise, all our initial deflections are obtained by actual measurements on the cars before delivery. Therefore it is hardly reasonable to suppose that the wider axle pad can affect the riding of the car when the springs are arranged to give the correct initial deflection with the axle in position. What we have always felt is that the increase in unsprung weight, and in the tendency of the front axle to take up a criss-cross vibration, somewhat impairs the riding of the car when driving fast over bad roads. (j) We have had on order for some days some front springs giving us 4.65" initial deflection to enable us to judge the true benefit likely to be obtained under general driving conditions from greatly increased flexibility on the front end of the car. Hs{Lord Ernest Hives - Chair}/W.A.Robotham. | ||