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 report discussing wheel shimmy, periodicity, and forces at critical speeds.
| Identifier | ExFiles\Box 29\1\ Scan103 | |
| Date | 8th October 1925 guessed | |
| cntd :- -6- 50 m/m (2.0") If one considers that the successive compressions and extensions take place 10 to 12 times per second and the oscillation of the wheels about their steering pivots are corresponding to two alternative forces of the same periodicity, one gathers how very considerable are the forces concerned at the critical speeds. P.S. We have stated previously that the periodicity of the shimmy appears to be the same as that of a wheel revolution. We have verified the facts within the limits of accuracy of our instruments. (a) With our registering instrument for 6.3" tyres and for 5.7" and 6.5" mounted on corresponding rims in place of those of 6.3" tyres. (b) With the slow motion kinema for tyres of 6.3". We have still to verify those of 5.7" and 6.5" with the kinema. contd :- | ||