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).
Resolving brake judder by reducing the angle of the Ferodo brake lining from 130° to 90°.
| Identifier | ExFiles\Box 85\1\ scan0145 | |
| Date | 27th July 1936 | |
| -5- (3) The standard brakes, operated by a high efficiency high output servo, without damping on the swinging arm, can be made to judder quite easily, and this combination has been used with every anti-judder scheme before we have finally decided that it is efficacious. (4) On a standard car, the Ferodo on each shoe is subtended by an angle of 130° at the hub centre. With standard drums, it was found that reducing this angle increased the difficulty of obtaining a judder, until the angle was reduced to 90°, when judders ceased on the car we were using. (see sketch). 4 130° 130° FRONT OF CAR 4 90° 90° FRONT OF CAR To make this change the tipping shoe was set solid. At first the result was thought to be associated with the wrapping action of the forward shoe, but it appeared subsequently that the freedom from judders was entirely due to the increased sponge in the brake system. | ||