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).
Conditions under which front wheel brakes might lock up or cause skidding.
| Identifier | ExFiles\Box 73\3\ scan0271 | |
| Date | 5th February 1925 | |
| 79946 PN{Mr Northey}11/DN5.2.25. TO Hs{Lord Ernest Hives - Chair} c. to BJ & CWB FROM PN{Mr Northey} FRONT WHEEL BRAKES. Are you able to say from tests you have made, under what conditions (if any) when driving along the straight, one or both of the front wheels may be locked on application of the brakes ? Naturally the proportion of braking fore and aft, has been arrived at primarily with a view to this consideration, and although it would appear to me probable that with ordinary legitimate use our system of F.W.B's would not result in locking and therefore skidding of the front wheels, it would seem to me to be likely that if a driver at a high speed used the footbrake very violently, one or both front wheels might be locked, even on a dry road. Do you agree to this proposition ? My reasoning is that when driving at 60 m.p.h., the front wheels are both intermittently off the ground to a great extent, and if when one of the wheels may be in the air, the footbrake is pressed violently, this wheel will probably be held from moving; meanwhile, the rear wheels not having skidded, will continue, as long as the pedal pressure is applied, to enable the Servo to operate on the front wheels, with the result that quite a developed skid or locking of the front wheel or wheels, might result. - In fact, these conditions were fairly well fulfilled two days ago when one of the Technical staff of "The Motor" was making deceleration tests with our 40/50 HP Open Car No. 11-AU. It is naturally of the gravest importance to us that we should be able to establish as far as humanly possible, that in the ordinary and reasonable application of our front wheel brakes, front wheel skidding is almost impossible. I have ascertained that the brake-shoes on the front wheel which was locked, have not worn in such a way as to leave the toe and heel without relief. There is plenty of clearance from both points, so that apparently there was no tendency to self-wrap from this cause. I cannot find also that there is any tendency to stickage in the compensating differential. PTO | ||