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).
Front brake clearances and adjustments, comparing the current system to the Bentley layout for the 20/25 model.
Identifier | ExFiles\Box 30\6\ Scan222 | |
Date | 19th October 1933 | |
X15359 26 To Wor.{Arthur Wormald - General Works Manager} from Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} C. E.{Mr Elliott - Chief Engineer} C. Hy.{Tom Haldenby - Plant Engineer} C. Ry. Da.{Bernard Day - Chassis Design} C. Hly. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}1/KT.19.10.33. X1360 BRAKES. We have fitted to 19.G.IV. the increased front braking now standardised on the 20/25. During the tests in question the clearances at the rear were 1" and in the front .5" and .6" at the end of the 4.000" lever. The front cam radius is .500" giving a final multiplication of 8 times. It was possible when the drums were hot to cause the servo to reach the end of its travel. New cars are sent out with brake clearances 1" at the rear and .500" at the front. The reason for this large clearance in the front is to prevent the brakes rubbing on lock. On adjusting the front brakes to .250" at the lever giving approximately the same clearance in the drum as the Bentley, the brakes rubbed on about half lock but would not seize on the road. Therefore, owing to the layout of the front brake operation, we have to waste .015 wear of the linings and start cars off in life with the brakes really requiring adjustment. It appears therefore that the Bentley brake layout is superior to that of the 20/25. We recommend that if the 20/25 can be altered so that the brakes can be set closer that this is incorporated with the easy adjustment. The 40/50 also requires the wing nut adjustment. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||