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).
High-speed wobbles and proposing two experimental tests to reduce them.
| Identifier | ExFiles\Box 52\1\ Scan154 | |
| Date | 19th September 1928 | |
| To DA. {Bernard Day - Chassis Design} from Hs {Lord Ernest Hives - Chair} /Rn. {Mr Robinson} Hs {Lord Ernest Hives - Chair} /RnL/LG19.9.28. With reference to DA {Bernard Day - Chassis Design} 3/M18.9.28. We are returning to you herewith all the literature that we have on high speed wobbles by Mr. Sensaud de Lavaud. The most useful portion is the summary in English; various paragraphs of which we have marked. These are in general agreement with our tests. The two points we are proposing to try experimentally are :- (1) The hydraulics arranged transversally so that the loading is applied over the pivot of the axle as near as possible. As far as we can see with this arrangement we definitely ought to be able to damp out wobbles with two-thirds the present shock absorber loading and should therefore be able to give more comfortable riding to a certain extent, though of course the parallel movement of the axle will be the only feature to gain, as the criss cross movement will be restrained as at present. Another advantage that we see of applying shock absorber load at the pivot is, any lost movement in the shock absorber or leakage will be minimised. We believe that frequently lost movement is what allows a wobble to start. (2) Our second test is to lock the differential and see if this in any way substantiates Mr. De Lavauds claim for reduction in 'shimmy'. Hs {Lord Ernest Hives - Chair} /Rn. {Mr Robinson} | ||