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).
Review of brake shoe design and lining areas for 40/50 and 25 HP models, with a comparison to competitor vehicles.
| Identifier | Morton\M19\ img090 | |
| Date | 16th December 1930 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Bm. c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} Da.{Bernard Day - Chassis Design} c. E.{Mr Elliott - Chief Engineer} Ry. Hs{Lord Ernest Hives - Chair}/Tml/AD16.12.30. X. 7930. X. 5360. X. 5930. X. 5420. X. 7360. X. 7420. 40/50 and 25 HP. BRAKES. Since brake shoe design is under consideration, we have been reviewing the average brake area provided per ton weight on various cars. It will be noted that we are below the average even on the wider rear brake P.II. We consider that we shall have considerable trouble with owners of the 26-EX type of car even with the new drums unless we increase our lining area on the 40/50; we are convinced that low unit pressures help to avoid squeaks and groans as much as adequate cooling. They also enable softer lining with less squeaking tendencies to be used. We believe that the modern automatic signal type of traffic control, which causes a complete stop, is a great factor in producing groaning brakes, and necessitates special remedies. We consider that though we shall be better off with the anti-squeak brake shoes and thicker drums, we could with advantage increase our lining areas. BRAKE LINING AREAS. TYPE OF CAR BRAKE AREA/TON TREAD WEIGHT ON TYRE. Latest P.II. 91 sq.in. 20/25 HP. 96 " Isotta 110 " Chrysler 77. 116 " Hispano 122 " Mercedes. 210 " Hs{Lord Ernest Hives - Chair}/Bm. | ||