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 vehicle suspension experiments concerning ride quality, shock dampers, and cornering roll.
| Identifier | ExFiles\Box 154\1\ scan0243 | |
| Date | 14th January 1935 | |
| -3- Hs {Lord Ernest Hives - Chair} /Les.14/KW.14.1.35. On the road Expt. II was not satisfactory. The increase in rating being too great, on a large bump the whole of the front of the car was raised and pitching followed. The riding in the back was poor. In order to prevent the car from being excited into a state of oscillation on a large bump, the road wheels must have sufficient freedom to prevent raising the front of the car. Shock damper loads increasing with the rating would appear to be useful with this system. The tendency for rolling was greatly reduced with this system. However, it is much better to prevent rolling with a torsion roll rod at the back, which does not upset the general riding of the car to such an extent. Expt. III is the simple lever mechanism which has up to the present given the best ride, and is now fitted to the car. Expt. IV is the rating curve we propose to try next. This can be fitted by changing the minimum number of parts. Shock Dampers. Considerable time was spent in France experimenting with an orifice damper, controlled by a taper needle. This allowed a large leak in the normal centre position which gradually was reduced as the wheel moved towards bump or rebound. As any orifice damper has a high pressure velocity effect - that is, the load increased with greater speed of the wheel - consequently the car receives the shock of a rapid wheel movement, which excites the car to pitch, but there is insufficient load to stop the comparatively slow movement of pitching. We are now fitting an ordinary type of damper with valves. Rolling on Corners. With the simple lever mechanism which at the moment gives the best ride, the car rolls badly. This will be overcome by fitting a roll rod at the back similar to SpectreCodename for Phantom III. | ||