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 steering geometry, pivot types, and their effects on vehicle handling and stability.
| Identifier | WestWitteringFiles\P\2July1926-September1926\ Scan206 | |
| Date | 22th September 1926 guessed | |
| contd :- -2- When negotiating very sharp bends at any speed, the steering becomes heavy owing apparently to the fact that the geometry of the steering is incorrect on a lock i.e., the Ackermann affect is not obtained in this experimental rig-up. Under these circumstances, the tyres can be heard scrubbing on the road. The general inferences to be drawn on this test are :- (1) Light shunting steering can be obtained with a vertical pivot, and quite an appreciable amount out of centre. (2) Transverse vertical pivots necessitate more backward pivot lean to obtain self centering unless some other means is employed. (3) Out of centre point steering gives a feel of stability at high speeds, and considerable immunity from road shocks. It does not however have any marked affect on high speed wobbles. It should be borne in mind, when comparing this axle with the standard, that its transverse moment of inertia is somewhat greater than standard, owing to the vertical pivot and wheel. This, in itself, is conducive to high speed wobbles. We are unable to obtain any signs of low speed wobbles. VERTICAL PIVOT AXLE WITH STANDARD BEARINGS, CENTRE POINT STEERING WITH DISC WHEELS, 6.2" BALLOON TYRE. ------------------------------------------------- With this arrangement the steering is agreeably light for shunting, compared with the new type axle. Self-centering is satisfactory, but not decisive with normal pivot lean. When necessary friction in the steering it becomes very sluggish. contd :- | ||