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).
High-speed steering wobbles.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan246 | |
| Date | 15th September 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. ORIGINAL EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}/LG15.9.25. 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} EY. c. to Wor.{Arthur Wormald - General Works Manager} HIGH SPEED STEERING WOBBLES. +457 X8420 We have compared the standard front axle of the pre front wheel brake era with that of a front wheel brake axle without front wheel brake parts. Both axles were fitted with 7.25" balloon tyres at 20 lbs/sq.in. We found that with the present axle without brakes we could obtain a wobble with balanced wheels at a speed of just over 60 m.p.h. This was not a severe wobble but could be maintained over an appreciable period. With 1 lb. out of balance we got a definite high speed wobble but not of any great amplitude. With the front axle of the type before we fitted brakes we could not build up a wobble with balanced wheels. We could get spasmodic shocks on the steering wheel but not a continuous wobble. With 1 lb. out of balance we still had very considerable difficulty in getting a continuous wobble. We should say that with this axle a customer would be immune from high speed wobbles unless the wheels were abnormally out of balance. The speed at which the wobbles occurred appeared to be the maximum of which the car was capable, i.e., about 65 m.p.h. As a rough basis of comparison, we should say that the present axle was 50% worse for wobbles. The only reason for this result is that the track of the present axle contd:- | ||