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).
Technical memo discussing the unexpectedly light steering and reduced stability of the KAC.VIII model's new axle due to pivot inclination.
| Identifier | ExFiles\Box 179b\3\ img154 | |
| Date | 22th September 1926 | |
| COPY. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. BJ. Mor. c. Ev.{Ivan Evernden - coachwork} Rg.{Mr Rowledge} c. E.{Mr Elliott - Chief Engineer} Rs.{Sir Henry Royce's Secretary} c. GY. Da.{Bernard Day - Chassis Design} KAC.VIII. STEERING PIVOT INCLINATION. The new axle gives remarkably light steering. While we expected the steering to be lighter than 'V' series owing to the new type of pivot bearing and increase in "out-of-centre" of tyre contact, we were not prepared for the very large difference actually obtained. In addition we were anxious to obtain some reason - (a) Why the new axle has not quite the feeling of stability at high speeds of the old axle. (b) Why, when the necessary friction is added to the new axle, though the steering is still very much lighter than standard, its self-centering is sluggish. We therefore conducted a series of tests on five different axle arrangements (See attached print). The results all shewed that for the same tyre contact the less the transverse pivot inclination the lighter the steering, the less the self centering and the less the stability at high speeds, though the stability cannot really be said to be poor even with vertical pivots. It is just the feeling that the steering has a slight tendency to "stay put". We expected this owing to the fact that the car has to be lifted on either lock when the pivots are raked transversely. We did not, however, expect to find such large differences as we encountered. | ||