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).
Analysis of front wheel locking under braking and steering heaviness, with a proposed solution to modify the braking distribution.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan140 | |
| Date | 23th November 1926 guessed | |
| contd :- -2- is very little margin to prevent the front wheels from being locked. Actually, in the extreme case of efficient front brakes and inefficient rear brakes, we believe that in service the front wheels of this car would be locked in an emergency. In any case, when fitted with large travel low rating side steering tube springs as at present, the axle of this car shews a very pronounced tendency to tuck under on even moderately severe brake application. We have tried increasing the backward pivot lean with a view to over-coming the trouble. Unfortunately this makes the steering heavy. In addition, it brings up low speed wobbles so that frictional or hydraulic damping has to be incorporated in the system. This makes the steering still heavier. Without either of these modifications, the steerings on large closed cars is hardly as light as could be desired. Therefore we feel that while we can go an extra degree back with the pivot lean, this is not a solution to the problem. In the absence of positive axle control, we consider that the only satisfactory palliative is to reduce the proportion of front braking. We suggest that we reduce the braking units to the front axle by 28%, which will reduce the percentage braking on the front wheels to 33% of the total instead of 40% as at present. This can be accomplished by increasing the length of the two levers on the front equalising shaft (G.73149) from 3.00" to 4.00" on EAC-Vll. At present the Test Dept. have a certain number of complaints about inefficient brakes on trial cars. contd :- | ||