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).
Suspension design, comparing spring types and the need for increased damping due to new tyre technology, specifically for the Goshawk 11 model.
| Identifier | ExFiles\Box 45\1\ Scan217 | |
| Date | 22th June 1921 | |
| Contd. -2- RIO/G22.6.21. than any other cars of equal weight carrying capacity. The springing is more frictionless than usual, and this new universal adoption of tyres 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 11, we are using non-cantilever semi-elliptic springs, 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 bewteen the axle and the frame, and it will be noticed that this is what we have done in our designs of Goshawk 11. R.{Sir Henry Royce} | ||