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).
On tests conducted on the 'SS' front axle to improve steering and reduce high-speed wobble.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan023 | |
| Date | 8th June 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/An. c. to B.J. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to EY. ORIGINAL Hs{Lord Ernest Hives - Chair}/Rml/LCl 8.6.28. 'SS{S. Smith}' FRONT AXLE. X-7420 X457 We have been running the present standard axle with stub axles so altered that the wheels are 1.75" out of centre point. The result is a marked reduction in the tendency to high speed wobble, also road shocks are reduced. The steering is no heavier for shunting, in fact, it is lighter if anything. This test confirms all the other tests we have done with wheels further out of centre point, except that now we also retain our light shunting steering. We attributed the good parking to : (1) Roller top pivot bearing reduces the effect of additional cross wind. (2) Small transverse king pin inclination makes it possible to go further out from centre point without having to lift the car much more on a lock. (3) Rolling of tyre tread increased, scrubbing action reduced. We note that N.sch:2625 shews that on the new dropped axle the tyre contact has gone out .237, though not the wheel centre. If it were possible we should like the wheel centre also to go out .250" at least. We think that with this experimental axle we can reduce both the friction in the system and the flexibility of the side steering tube springs as both of these are at present controlled by high speed wobbles and road shocks. Thus we can automatically improve the selectivity of the steering. contd :- | ||