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).
Brake and steering tests in France, detailing issues with the steering taking charge when braking on full lock.
| Identifier | Morton\M20.3\ img030 | |
| Date | 26th June 1924 | |
| B.R. 493A (20H) (D.A. 652 20-3-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. 9941 9940 REF: H-S/A.C.C./26.6.24. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. EH. c. to DA.{Bernard Day - Chassis Design} E c. to EY. WOR.{Arthur Wormald - General Works Manager} SECRET. ADOPTED SCHEME OF BRAKES - TESTS IN FRANCE. The two cars in France (35-PK and 98-NK) had completed 5307 and 5322 miles respectively on 22.6.24. 35-PK completed 5000 miles before the brakes needed adjustment. A complaint on both cars which has developed worse with running, is that if the brakes are applied when the steering is on the lock, the steering takes charge and runs away on full lock. The lean of the pivots on 35-PK was checked and it was found that with the frame level they were leaning .100" forward. When the car left Derby they were set the std. amount which is .150" backwards. Investigations are being carried out to find whether the alteration to the pivot lean has come about due to the stretching of the front spring clips or alteration of the front springs. When the pivot lean has been restored to normal, the steering still has a tendency to take charge on corners and is worse in this respect than it was at the beginning of the test. This we attribute to the fact that the steering has become freer with running. We know that with some of the present standard cars, if we do not keep within fine limits as regards the lean of pivots, if a corner is taken at speed, it is possible for the steering to take charge. We know from the measurements taken of the twist on the axle that the steering will take charge if the brakes are applied hard on a sharp corner. contd:- | ||