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).
Investigations into high-speed steering wobbles and the effect of castoring angle.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan326 | |
| Date | 1st September 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF Ha/Rm{William Robotham - Chief Engineer}1/L029.9.25. To R.{Sir Henry Royce} from Ha/Rm.{William Robotham - Chief Engineer} c.c. to C.J. B. c.c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c.c. to DA.{Bernard Day - Chassis Design} EY. c.c. to Wor.{Arthur Wormald - General Works Manager} HIGH SPEED STEERING WOBBLES. +457 We have been carrying out careful investigations to determine the exact effect of castoring angle on a standard Phantom axle and pivots. These tests were conducted on the dynamometer drums. The wheels were toed in a quarter of an inch at the front. We find that we can obtain wobbles with a forward pivot lean of 4º. There is a steady decrease in the violence of the wobbles as we go forward with the pivots starting at 4º backward lean. This improvement is only slight however. When we go from 4º forward to 6º forward, there is a very marked improvement, and beyond this we were unable to produce high speed wobbles. We know that with 6º forward lean, road tests show that all self-centering has not disappeared owing to the transverse inclination of the steering pivot. At the first opportunity we are trying a standard axle with vertical pivots which is at present being made. We have, in addition, been running a car without a side steering tube. We find that although we arranged the car so that we got violent wobbles when the side steering tube is coupled up - when it is disconnected we cannot get wobbles to build up. contd :- | ||