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).
The performance and issues with a car's four-wheel braking system.
| Identifier | WestWitteringFiles\K\November1923\ Scan9 | |
| Date | 12th July 1923 | |
| R.R. 403A (40 H) (SL 42 12-7-23). J.H. D.{John DeLooze - Company Secretary} -2- EXPERIMENTAL REPORT. Expl. No. 4609 REF: HEQ/LDS.11.23. is of the most consequence. If it were not low, it would certainly never attain a road speed of 60 m.p.h. with a maximum road wheel H.P. of only 46.5. Braking. This car is not a good example of 4-wheel braking. The drums are springy - the cooling fins on them being so small that their main function appears to be to catch the dirt. The front wheel brakes are distinctly poor, though for our tests we adjusted them to obtain the maximum braking possible. In this condition, when braking on corners above 15 m.p.h., the steering was seriously affected tending to take charge. This is possibly why the front brakes are not made more powerful. The only extra provision for taking the torque on the axle due to front wheel braking appears to be an extra reversed leaf in the springs and wider spring seats on the axle; the axle from the springs outwards is also of stiff section. The rear brakes, when operated alone, are quite good. The figures given for the Goshawk are without locking the rear wheels; above 20 m.p.h., up to which speed the throttle opening was manipulated by the hand control, the foot had first to be taken off the accelerator pedal at the signal to stop, that is why the braking at 20 m.p.h. appeard relatively better than that at the higher speeds. Rm.{William Robotham - Chief Engineer} contd:- | ||