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).
Page from a technical note discussing the causes and mitigations of wheel wobble and shimmy.
| Identifier | ExFiles\Box 170\3\ img052 | |
| Date | 20th June 1935 guessed | |
| -lc- (5) cont'd.{John DeLooze - Company Secretary} occurring at a much lower speed. Not depending on tramp. Not depending on wheel unbalance. Not depending on gyroscopic effects. (6) The cycle of wheel movement in wobble is similar to the initial stage of shimmy. (7) Several varieties of wobble exist, each corresponding to the rocking of the car about a different axis. The most dangerous variety is that which occurs when the drag link is removed or the steering gear breaks. (8) The effect of engine mount on wobble is not understood but may be very great. This suggests that all new models should be tested on smooth drums for wobble and the engine mount adjusted by trial until it has no harmful effect. (9) To reduce wobble (as also for shimmy) it is obvious that wheels should be set parellel in plan view and not toed in. (10) Weight balance around kingpin appears to favour a perfectly balanced assembly, that is, in side elevation the kingpin centre line should run through the centre of the swinging mass. kingpin (11) Large overhang of wheelplane from king-pin & large angles in front elevation should be avoided. (12) Stiff frames have the effect of improving wobble conditions. | ||