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).
Recommendation to fit Hartford pattern double-acting shock dampers to the 40/50 chassis to counteract issues caused by the increased resilience of cord tyres.
| Identifier | ExFiles\Box 39\2\ Scan137 | |
| Date | 10th February 1922 | |
| X3538 To RR. of America Inc. from R.{Sir Henry Royce} for the attention of - Mr. Belnap. Mr. Olley. Mr. Nadin. c. to CJ. BJ. c. to FN. Hs.{Lord Ernest Hives - Chair} c. to BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} c. to Hm.{Capt. W. Hallam - Head Repairs} R2/10.2.22. RE. REAR SPRINGS. X.2628 X.3538 X.3461. X.4426 You will remember that much trouble has been experienced owing to the increased resilience of the cord tyres. The trouble has been considerably reduced by taking care not to pump the tyres at too high pressure for the load. We are running our open cars at 50 sq.ins. for the rear tyres. It has been noticed that there is very little real difference in the friction of thick and thin leaf springs, when they are both well lubricated, but owing to the increased resilience of the tyres it is necessary to have more damping effect between the axle and the body, especially at the rear end of the car. Mr. Hives and Mr. Platford and all of us agree that we cannot afford to use the progressive type of shock absorber on our 40/50 chassis, and that the best proposition at present available is to fit the Hartford pattern of double acting shock dampers at the rear of the car. This fortunately can be easily and conveniently done. The advantage derived from fitting these shock dampers is (1) considerable reduction in the tendency of the transmission to knock, and (2) the jaggering of the back axle on the application of the brakes, (3) vibration of the back axle when starting a car backwards during shunting, and (4) the steadiness of the riding especially at high speeds. It is therefore our recommendation contd:- | ||