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 braking performance of the Phantom model, discussing wheel lock and retardation.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan110 | |
| Date | 2nd November 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. ORIGINAL EXPERIMENTAL REPORT. Expl. No. REF: [Text Struck Through] Hs{Lord Ernest Hives - Chair}/Rml/LG2.11.25. To DA.{Bernard Day - Chassis Design} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} PHANTOM BRAKING. 48220 With reference to DA{Bernard Day - Chassis Design}2/M31.10.25. We have found in practice that it is possible to get more braking on the front by a very violent and rapid depression of the brake pedal. Practically, however, even on a car on which we have occasionally been able to lock all four wheels at once, we have not measured a retardation in excess of 20 ft/sec2. We consider that although the flywheel effect of the wheels and rotating portions of the engine materially influences the pedal pressure required to lock the wheels under certain circumstances, they can of course have no bearing on the minimum stopping distance of the car, provided the wheels can be instantaneously brought to the point of [strikethrough: locking]. maximum braking without locking. Hs{Lord Ernest Hives - Chair}/W.A.Robotham. | ||