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).
The causes of vehicle wobble, focusing on tyre damping, tread patterns, and other contributing factors.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan245 | |
| Date | 15th September 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. C EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG15.9.25. primary importance as they dictate the speed at which the wobble takes place. We believe the damping of the tyre is also important, but in addition that we shall now find the nature of its tread pattern to be a potent factor. We believe that to a large extent the tyre manufacturer is responsible for a low pressure tyre wobble ever starting, quite apart from the balancing of wheels. The problem of making a low pressure tyre which will not cause periodic axle movement on the road would appear to be one of the greatest difficulty! We do not now consider that the gyrostatic couples due to the rotating masses of the wheels being angularly displaced are worthy of serious consideration. This is confirmed by our road test in which we increased the rotational energy of the wheels 25% and could detect no change in the violence of the wobbles. We believe that we shall be able to obtain some relief by a careful study of tyre contact which minimises the reaction of the road in a wobble. Transverse damping and the criss cross axle period still maintain their previous position of vital importance. We now know that some of the contradictory results which we have obtained on the road have been directly due to moisture on the surface masking the wobble. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||