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 report on an experimental four-wheel braking system, noting issues with brake balance and performance.
Identifier | ExFiles\Box 73\2\ scan0338 | |
Date | 23th April 1924 | |
f9940 PN{Mr Northey}6/DN/23.4.24. TO Hs.{Lord Ernest Hives - Chair} FROM P.N. I ran the Experimental car having the four wheel brakes, about 300 miles and found that for high speed touring, the braking forward was very pleasant and effective. I felt, however, that the whole of my run from the test point of view, was a wash-out, because of the degree to which the rear brakes were effective before the front brakes, that is, on every occasion when the brakes were applied at all vigorously, the rear tyres skidded, so that I imagine had any of the roads been wet or greasy, (which they were not,) I should have been continually correcting rear skids owing to the rear wheels being braked too much and the front brakes not having sufficient share of the work. I trust that it is intended that all four wheels should be braked evenly in extent. A very peculiar condition arises when driving slowly on top gear in traffic, which is quite different to what I noticed with the Hispano brake system. It is difficult when driving in a queue of cars at about 6 - 10 miles an hour with intermittent stops, to prevent the Servo mechanism taking charge and pulling the car up dead at a time when one wished to reduce speed only. Doubtless with excessive skill one could avoid this happening, but in the hands of the ordinary man, there would have been a constant tendency to pull the car up. Meanwhile, one's foot gets the impression that it is being pushed into a bank of stiff mud. The rear braking, as I had been informed, was extremely poor. I was glad to have an opportunity of trying these brakes, which give some indication how important an improvement this system must be when in its final form. There was no trouble of any sort. P.N. P.N. | ||