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).
Comparing reversed and rebound leaf springs fitted to Lancia and Bentley vehicles.
| Identifier | ExFiles\Box 42\3\ Scan205 | |
| Date | 10th August 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} X3854 Hs{Lord Ernest Hives - Chair}/Rml/LG10.8.26. X4048 X2628 REVERSED AND REBOUND LEAF SPRINGS. X.3854 X3805 We have been making some comparisons between the reversed leaf spring as fitted to the Lancia, and the rebound leaf spring as fitted to the rear of the Bentley. We find that the rebound leaf spring has little more internal friction then a standard spring. We have tried them on the road and the car riding does not seem to be impaired appreciably. Their life on the bumping rig is about 40% greater than that of a standard spring. They seem to have slight torsional advantages. We suggest that the rebound leaf opens up possibilities of increasing the life of the front springs. Reversed leaves definitely increase the spring internal friction. This will be clearly seen from the attached spring hysterisis curve. In addition the reversed leaves clearly lower the spring rating, therefore the spring must be heavier for a given rating than if the reversed leaves were not employed. Over bad roads this spring seems to have definite riding advantages. We have had no opportunities of determining the relative life of this type of spring as yet. We do not like the principle of increasing the internal spring friction because this type of friction is uncontrollable, must vary widely with the condition of the spring, and is always difficult to measure. However we suppose Lancia's are unable to obtain a shock damper which will give them the amount of damping they require and yet stand up to Italian roads. Hs{Lord Ernest Hives - Chair}/W. A.{Mr Adams} Robotham. | ||