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).
Test results for 25 HP brake clearances to prevent seizure.
| Identifier | ExFiles\Box 102\3\ scan0059 | |
| Date | 25th July 1932 | |
| To Mx.{John H Maddocks - Chief Proving Officer} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} x5360. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}14/MJ.25.7.32. 25 HP. BRAKES. As you know there has always been a tendency for the 25 HP. brakes to seize on when driven hard. We have carried out some tests which shew that the absolute minimum of clearance for the rear brakes with the Hancock shoe is .750" and with the Hancock shoe is 1" measured at the brake lever on the axle. Actually this should be the minus limit. As far as we can measure the front brakes do not suffer from this trouble to anything like the same extent as the rear brakes and do not require a very large clearance. We should be interested to have your views on these results. We think the silent third speed is going to make people drive much faster down winding lanes and use their brakes more in consequence. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||