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).
Investigating the causes of high-speed steering wobbles.
| Identifier | ExFiles\Box 29\1\ Scan051 | |
| Date | 15th September 1925 | |
| R.R. 495a (50 H) (D.D. 31. 12-6-25) J.H.D. +L57 Expl. No. REF HS{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG15.9.25 EXPERIMENTAL REPORT. 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. +8810 Our tests running the front wheels of the car on drums have enabled us to ascertain the following. Previously we have been unable to find out - (a) What causes the period of the wobble to coincide with the period of a wheel revolution when it starts, the wheel being balanced statically. (b) What feeds the wobble once it has started, and makes it build up to the alarming proportions experienced. (c) What the true value of the gyros tatic couple is in causing the wheels to turn in and out. In connection with point (a), we balanced the wheels statically and then ran them at slow speeds on the drums so that the centrifugal effects of any dynamic put of balance would be negligible. We observed that the axle <strikethrough>show</strikethrough> moved up and down an appreciable amount with a frequency corresponding to the wheel's revs. This was due, we believe, to the tyre being eccentric with the rim. Each tyre had a spot on it where the axle was raised. When these two spots were in step the axle moved up and down with a parallel motion. When out of step, with a criss <strikethrough>XXX</strikethrough> cross motion. We placed an indicator on the spring pad and slowly rotated the wheel. We found that on one side of the tyre the axle was raised .060" higher than on the other side. This was less than contd :- | ||