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).
Investigations into high-speed steering wobbles.
| Identifier | ExFiles\Box 28\4\ Scan264 | |
| Date | 1st August 1925 | |
| R.R. 488a (50 M) (D.D. 21. 12-6-25) .H.D. EXPERIMENTAL REPORT. Expl. No. +457 REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG12. 8. 25. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} HIGH SPEED STEERING WOBBLES. We have been carrying out investigations on this phenomenon to ascertain what possibility there is of alleviating the trouble on standard cars. As has been previously stated in experimental reports, we find that the most important factor with regard to this problem is wheel balance, 1/4 lb. out of balance of the wheels is often sufficient to promote the tendency to wobble. We received information to the effect that increasing the toe-in or wheel gather was lightly to reduce high speed steering wobbles. We have carried out a number of tests to prove this point. From our results we do not consider that we shall be able to affect high speed steering wobbles materially by increasing or decreasing the toe-in of the front wheels by the amount which would be permissible if reasonable tyre wear is to be obtained. The general tendency appears to be that if the toe-in on the car is increased beyond a certain amount, high speed steering wobbles increase in intensity - if the wheels are towed out on the other hand, the wobbles are reduced. We have carried out tests to check the effect of tyre pressure on high speed wobbles. As has been stated in previous memos, we found that increasing the tyre pressure increases the frequency of the wobbles and decreases its amplitude. contd :- | ||