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).
Twisted front axle on a 20 HP car with 4-wheel brakes.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan256 | |
| Date | 16th September 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}2/LG16.9.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} 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} 20 HP. CAR FITTED WITH 4-WHEELBRAKES. X5420 X5940 One of the standard production cars on test has badly twisted the front axle due to the application of the brake and the steering taking charge and going on to full lock. The proportion of braking and the leverages on the production cars is the same as on the 10,000 miles test car. The proportion is 1:1 or 33% front. The chief cause of the axle being twisted appears to be the steering taking charge. Once the steering gets on to full lock it would only require a very light braking on the front, if any, to lock the wheels and cause them to skid. We know that very modest front braking is sufficient to twist the axle forward and get the castor angle in the wrong direction. If we make the steering more irreversible it should reduce the tendency to take charge, although as long as we have any self-centering it is possible to happen. Attached is a report which explains how the axle was damaged, also a sketch showing where the axle is twisted. Hs.{Lord Ernest Hives - Chair} | ||