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 and rear brake performance, locking issues, and endurance test results.
| Identifier | ExFiles\Box 73\3\ scan0275 | |
| Date | 25th September 1924 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF: hel/LGS.2.25. is relieved on the front wheels by the car bumping, there would be a tendency for the wheels to lock. If we are going to have reasonable braking on the front, we see no way of overcoming this. You will remember that several cars we have sent to you recently, you have complained that the brakes were not as effective as the Trials Car brakes, and were not in your opinion, passable. This means, of course, that the Trials Cars have got efficient front braking. Although the leverages are arranged to give a greater proportion of braking on the rear wheels, this balance can easily be upset by the condition of the brakes themselves. We have known this for some time, but it has been very clearly proved by recent tests on the 20 HP. brakes that we can by no alteration, except the bedding and the setting of the brake shoes, make a 20 HP. brake so that with a light pressure on the foot pedal, the rear wheels are locked. On the other hand, if the bedding is incorrect, no amount of pressure will give you an effective brake. The only way of reducing the risk of the front wheels being locked is to reduce the front braking and, of course, as soon as you do this, you will reduce the efficiency of the brakes on a greasy road. With reference to PN{Mr Northey}4/IN5.2.25. A number of tests have been made running 4-wheel brakes to destruction. In every case the rear brakes have failed before the front. During the 100,000 miles run in France, we never wore out or damaged the front brakes but the rear brakes frequently had to be contd:- | ||