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 memorandum discussing modifications to the cross steering arm and investigating the causes of high-speed steering wobble.
| Identifier | ExFiles\Box 28\4\ Scan294 | |
| Date | 18th August 1925 guessed | |
| contd :- -2- modification to the R.H. cross steering arm which will require another ball. Particulars of this will be sent you today, and the designs for the hydraulic damper will be sent this week. In the meantime we are assuming that you are fitting a temporary a Houdaillle damper, after having cancelled the valves, and the central clearance if provided with it. In conclusion, we are assuming that the above will make our steering less affected (also driver feels less) from the speedwobblesfromthe [struck through] following sources :- (a) road shocks, (b) pot holes, (c) low speed wobbles, (d) high speed wobbles, and (e) taking charge when cornering. It remains to be seen whether each modification justifies itself, and does not introduce other harmful features, and whether we have done enough to consider that our steering is entirely satisfactory. It will be understood that the high speed steering wobble is to us quite a recent phenomenon. We had never heard of it until an attempt was made to use balloon tyres for high speed work. We believe however that in our case it is more prevalent because of the extra weight of the front axle, and of the front of the car, lower pressure tyres carrying great load, and the cord tyres having less internal damping. There is just the odd possibility that we have relative- ly some addition flexibility to the front of the cahssis, and DA.{Bernard Day - Chassis Design} has sent you particulars to test to see whether this has any influence on high speed wobbles. At the same time we do consider that in addition to the influence caused by the lean of the pivot and the tyre pressure, that the weight of the front axle alone, contd:- | ||