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 steering wobbles observed in cars fitted with balloon tyres.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan121 | |
| Date | 25th September 1924 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG24. 8.25.C To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} HIGH SPEED STEERING WOBBLES. Y457 Y4630 We find by calculation from our Chronograph record that the amplitude of a fairly bad high speed steering wobble occurring on a car fitted with balloon tyres is approx. 17°. The periodic time of one wobble was .117 secs. The time taken to swing through 4° each side of the centre in one direction was .018 secs. Assuming the moment to be S.H.M., this gives a total amplitude of 17°. We have confirmed the fact that adding weight to the brake drums increases the amplitude of the wobbles and increases the tendency for these wobbles to be set up. The latter tests were carried out with balloon tyres on a Silver Ghost model - the previous tests on a 'Phantom'. Hs.{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||