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).
Evolution of suspension design, comparing spring types and the necessity of increased damping friction due to changes in tyre construction.
| Identifier | ExFiles\Box 180\M1\1\ img037 | |
| Date | 21th June 1921 | |
| To C.J. from R.{Sir Henry Royce} R10/C22/6/21 Contd. of cord construction calls for considerably increased damping friction of the axles. It may be probable that we shall be forced into the use of shock dampers in addition to thin leaved springs. In "Goshawk II" we are using non-cantilever semi-elliptic spring, and as we are controlling the back axle by the spring, the back axle itself can be of lighter construction, as it is relieved of many stresses which it has to bear when controlled by a central sphere. It will therefore be noticed that inverted canti-lever springs do not really give the advantage of less unsprung weight, owing to the above remarks. They do, however, if made of equal length, result in considerably less friction, owing to their deflection being halved for a given movement of the back axle. In pre-War days we considered that this absence of friction was advantageous, but since the recent departure in tyres, it is definitely necessary to have more damping friction between the axle and the frame, and it will be noticed that this is what we have done in our designs of "Goshawk II". R.{Sir Henry Royce} | ||