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 effects of unequal front braking and pivot lean on the steering of a 40/50 HP car.
| Identifier | ExFiles\Box 182\M20\M20.2\ img041 | |
| Date | 15th May 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} ORIGINAL EXPERIMENTAL REPORT. Expl. No. X.9940 REF: Hs{Lord Ernest Hives - Chair}1/LG15.5.24 x9470 S E C R E T. FOUR-WHEEL BRAKES, SIDE DIVING WITH UNEQUAL FRONT BRAKING To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. RG.{Mr Rowledge} c. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to HY.{Tom Haldenby - Plant Engineer} WJR. We have not been satisfied with the way in which the steering on the 40/50 HP. is affected by the unequal braking on the front of the car. We have noticed considerable difference between various cars. It is difficult to get brakes to give equally the same braking affect and even if the brakes are equal, if one wheel is on a patch of grease, when the brakes are applied, the same action can take place. We have carried out a series of tests which go to prove that there are other factors besides the one pointed out by DA.{Bernard Day - Chassis Design}, which can affect the steering of the car when the braking is unequal. We have taken a 40/50 HP. car and disconnected one of the front brakes. Under this condition the car steered in the direction in which the wheel was braking. It required considerable effort to prevent the steering taking charge. With the car under this condition, we tried the effect of different leans of pivot. We found if we had the pivots vertical or leaning slightly forward, immediately we put any pressure on the one front brake, the steering is immediately turned and it requires considerable power to hold against it. If, with the car in this same condition, we run backwards and apply the brakes, the car maintains a fairly straight course when the brake is applied. If we then modify the pivot lean so that it is definitely leaning backwards, say twice the standard amount, we then do not contd:- | ||