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).
Vehicle suspension issues, including spring ratings, deflection, and steering complaints on the Phantom I.
| Identifier | ExFiles\Box 16\4\ Scan156 | |
| Date | 14th May 1930 | |
| -3- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/W.J.14.5.30.Contd. 'bus services. This complaint cannot be dealt with by the rear spring rating, at present we should say that the majority of the cars leaving the Works have over 9" rear spring deflection under full load which means that they are on the absolute limit and we are getting complaints of hitting the buffers. On the other hand, they cannot have much more than 3" front deflection without striking through. We think that we have gone too far with flexible rear springs and not far enough with flexible front springs. The attached note from Hm.{Capt. W. Hallam - Head Repairs} indicates the results obtained with the 4½" deflection front springs on Phantom I. We agree that the steering is adversely affected by these springs but we consider that we shall have to work to get it right, though naturally the lower rating front springs ought not to be fitted to anything but purely luxury type vehicles. Apart from these weaker front springs, we have made little or no progress in dealing with this trouble. As a standard compromise we can reduce pitching slightly by increasing the damper loads, but this is likely to bring up the 20 M.P.H. complaint of dithering. It is of interest to note that by means of their double rating front springs the Lancia Lambda run on an initial deflection of 7 3/4" and the higher rating auxiliary spring does not come into operation until after a further 2 1/2" deflection of this very weak spring. The fact that this car has a selective steering at high speeds is rather remarkable, though of course it is far from being ideal from the point of view of road shocks. | ||