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).
Issues with cantilever springs and advocating for the urgent adoption of shock absorbers.
| Identifier | ExFiles\Box 78\2\ scan0200 | |
| Date | 8th November 1919 | |
| R.R. 235 x 100 T: (S F.{Mr Friese} 575, 16.4.19) G 2354 X.34616 COPY. To C.J. from R.{Sir Henry Royce} R2/GB.08.11.19 X 3461B RE SHOCK ABSORBERS. My Dear C.J. You will remember from the very earliest introduction of the canti-lever spring, that there were certain complaints about the riding of the cars fitted with these. We found, however, in France that it was to a large extent due to the springs being too stiff. We then softened the springs to our usual standard deflection, which allowed the axle to approach the frame by 5" or 6" at normal load, leaving 4" or 5" for oscillations. Then there were various controversies about springs which were greased and springs which were not greased. The point was that the cantilever springs, owing to their proportions naturally had very much less friction than springs of the semi-eliptic pattern, the result being, that they rode excellently over rough obstacles at low speeds, but my tests over the undulating roads in the Fens shewed a car with well greased cantilever springs to oscillate alarmingly. Nothing was found to give the combined effect of smooth running at low and high speeds until Shock Absorbers of the present type were tested. Now I am very anxious to get these put on the car as quickly as possible, because I am sure that the worst features of any car, including our own, is derived from the roughness of the road, and as such fittings as the shock absorbers do not constitute a danger, and are not likely to let us in for serious trouble, such as a broken frame or steering gear, I strongly recommend them to be fitted as soon as ever possible, continuing our bumping, and 10,000 miles tests while they are being constructed. The remarks you make that every fitting which has proved a benefit to the running of the car should be introduced as quickly as possible, supports this view, and you will remember that I suggested they should be fitted to the trial cars, and it is only reasonable to suppose that the customers will require their own cars to ride equally well. They permit of the combination which we have always tried to obtain, namely, soft springing with sufficient damping to prevent undue oscillations, and reduces the risk of bumping of the axle on the frame. One has only to experience the difference with either these back shock absorbers, or the standard front ones on some of the roads I have travelled on during this year, to realise the importance and urgency of the matter. I have had car with and without back, and with and without front shock absorbers and find both are very advisable Yours ever (sgd) R.{Sir Henry Royce} | ||