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).
Summary of steering experiment results for chassis 21-G-IV, detailing three modifications and their performance.
| Identifier | ExFiles\Box 101\4\ scan0120 | |
| Date | 26th October 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} x500 a Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}6/KW.26.10.35. Steering Experiments on 21-G-IV. Tests carried out up to date and results :- 1st change on 21-G-IV. Correction of cone angle of roller bearings at ends of cam. Result estimated as 25% improvement. Snatchometer Figures. Kegworth 4.27 turns. Six Hills 10.73 turns. 2nd change on 21-G-IV. Timken bearings on cam and roller. Snatchometer Figures. Kegworth 4.62 turns. Six hills 8.37 turns. 3rd change on 21-G-IV. Reduced helix angle with Timken bearings on cam and roller. Long pendulum lever to keep overall ratio as before. Snatchometer Figures. Kegworth 3.54 turns. Six Hills 4.58 turns. | ||