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).
Experiments conducted on a Bentley standard brake servo scheme to address judder and thump issues.
| Identifier | ExFiles\Box 85\1\ scan0144 | |
| Date | 27th July 1936 | |
| -4- Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}2/KW.27.7.36. A very considerable number of experiments have been made, most of which are described hereunder. They were carried out on a Bentley unless otherwise stated. (1) The standard scheme, here shown diagramatically, does not easily judder or thump, provided that the standard servo is used, the swinging arm poundage correctly set, all spring tensions are as stated, and the Ferodo is in good condition; i.e., it has never been overheated. [Blueprint text] 1. LINE OF BRAKE CABLE STANDARD SCHEME FRONT OF CAR (2) The standard scheme but without any swinging arm damping, can be made to thump and judder fairly easily on rapid brake application. Herein a danger lies: after long use the swinging arm damping becomes less effective as the Ferodo wears, and customers may experience judders in emergency braking. | ||