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).
Front axle control, discussing issues with spring stiffness, braking torque, and the testing of radius rods.
| Identifier | ExFiles\Box 72\3\ scan0276 | |
| Date | 9th July 1924 | |
| X9421 To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to W. BJ. c. to Wor.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} c. to Da.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} c. to PN.{Mr Northey} S E C R E T. R3/M9.7.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. RE FRONT AXLE CONTROL. X.9420. X.9421. X.9840. I was pleased to hear that the adverse criticism of 46-PK. was caused by the wrong springs being fitted, because if we depart from this more simple arrangement we shall be up against greater cost and complication in the first instance, and more difficult maintenance always, all undesirable qualities. It will be remembered that our front springing was thought to be too flexible for the clearance available, and for the length of the springs. The result was that at high speeds we get severe bumping, or overstressed or broken springs. So that under any circumstances it was thought advisable to increase the stiffness of the springs, and in a new model to lengthen the springs as much as weight and appearance would permit. This has been done. It will be remembered that I have always advocated that less than half the braking should be on the front wheels, and that springs of the rigidity required for other reasons should be capable of carrying the braking torque without undue stress or deflection. It was also understood that this was all the complication and change we could make at the present moment, until we found something that was more practical and simple than anything known. Of the best known control we think that a pair of radius rods, or a single radius rod and the spring is probably the best. We have wired the Works to test the single radius rod instructed, at once, in case it is desired to fit the best compromise. We are fully aware that this has some theoretical objections, but we shall be pleased if the Works will say how much this theory shews itself in practice. I fear we may come to some unwise conclusions perhaps from the fact that we shall be inclined to make the braking enormously powerful, and frequently used, whereas on an ordinary car, and under ordinary circumstances, the brakes do not get such important attention. We have been working at various parts of the braking system for alternate methods of construction, and these we are proposing to try when we are fitting up the Conhawk, but we must expect that if we add anything to a car, such as these brakes, there will be certain disadvantages, caused by the extra weight and the limitations thrown upon the construction by the presence of the additional parts. contd :- | ||