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).
Test report comparing a vertical pivot front axle with a standard axle, focusing on handling characteristics with balloon tyres.
| Identifier | WestWitteringFiles\P\2July1926-September1926\ Scan205 | |
| Date | 22th September 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c.c. to EJ. Wor.{Arthur Wormald - General Works Manager} c.c. to RG.{Mr Rowledge} c.c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c.c. to CY. Hs{Lord Ernest Hives - Chair}/RMd/LG22.9.26. VERTICAL PIVOT 3.5" OUT OF CENTRE POINT. X7420 STANDARD PIVOT BEARING FRONT AXLE, 6.2" X7430 BALLOON TYRES! (We took a standard V.{VIENNA} series axle arranged with vertical king pins and pivots to give horizontal stub axles, to France with us during our recent tests. By using disc and wire wheels (we obtained special disc wheels to take balloon tyres) we were able to obtain widely differing tyre contacts. The two arrangements gave the following results):- The most noticeable feature of this axle is its comparative immunity from road shocks at all speeds. Actually, with regard to high speed wobbles, its behaviour is not very different from the standard axle! For shunting, it is somewhat lighter than the standard axle. Self-centering with normal pivot lean is sluggish. It is clear that if a pivot has a considerable transverse lean and a wheel is fitted giving a large amount of out of centre point, the car will have to be lifted through an appreciable distance when the wheels are turned on either lock. With a vertical pivot, however, this difficulty does not exist. This possibly explains why this axle requires less effort for steering when shunting. At high speeds, the steering gives a nice sensation of stability, and as previously stated, the immunity from road shocks is very good. contd :- | ||