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 judder experiments and potential solutions involving brake linings.
| Identifier | ExFiles\Box 84\2\ scan0112 | |
| Date | 28th February 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}1/Km.28.2.34. (e) Adjusting the axle control so as to increase the backward pivot lean. If the axle then moved back as a whole when braking, the load would not be removed from the pad at the back of the shock damper ball end. The last experiment we carried out on the Trials Car, B-47-AE, was to fit steel carrier plates and increase the thickness of the material in the outer carrier member from .104" to .128". This appears to be an improvement, only a slight grunt being obtainable as the car comes to rest. This needs confirming by Sales after the car has stood all night with wet brakes, which condition produces the worst judders. We have also visited Ferodo's to obtain their suggestions for overcoming the trouble. They tell us that a hot brake lining in contact with a wet drum shows very high coefficient of friction, which would cause grabbing of the wrapping shoe which in certain conditions will produce a judder. They are supplying us with various linings to try of the Bendix type, low normal coefficient of Friction with no sudden rise when hot and wet. We shall report on these shortly. Hs{Lord Ernest Hives - Chair}/H.{Arthur M. Hanbury - Head Complaints} Grylls. | ||