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).
Analysis of chassis and steering wobble, discussing causes, testing methods, and reduction techniques such as adding friction.
| Identifier | WestWitteringFiles\J\January1923\ Scan24 | |
| Date | 12th January 1925 guessed | |
| contd:- -4- instead of having the weight bolted to the under-side of the crankcase we fixed it to the top of the crankcase, wobbles could be built up. If we take a chassis which has wobbles and we insert blocks between the spring and the frame and then bolt the axle and the frame together so that the front is solid, this will practically get rid of any wobble which builds up into a period, but one has the feeling that the wobble still exists. If we run a car on a dead-smooth road, with the cross steering rod dis-connected, we can start both front wheels wobbling by just flicking the one which is being steered. Radius rods reduce the tendency for wobbles. We have confirmed this a number of times because we could not see any reason why they should. Friction in any part of the steering except on the steering wheel, will reduce wobbles. We find that if the ball joints on the cross steering rod are tightened sufficiently tight, it will damp out wobbles. If sufficient friction is supplied to the ball joints on the side steering rod, that will also damp out wobbles. For this reasons, springs which are not set up assist in damping wobbles by applying friction on the ball ends. The period of the front springs on the 40/50 car which was tested for wobbles was 140 per minute. We have also carried out steering wobbles tests on the Marmon and Delage cars. The Delage will wobble very nearly as bad as our own car, especially if we increase the flexibility in the side steering rod. The period of the wobbles contd:- | ||