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).
Letter from the Experimental Department discussing car steering, understeering, and damper performance.
| Identifier | ExFiles\Box 154\1\ scan0299 | |
| Date | 3rd November 1936 | |
| 81305 Exptl. Dept. Rm {William Robotham - Chief Engineer} /Les.12/JH. 3rd Novemeber, 1936. Gordon Armstrong Esq., The Gordon Armstrong Patent Suspension Co.Ltd., Waltham Works, Beverley. Dear Armstrong, I hope your car reached you in satisfactory condition on Saturday. We all think the steering of the car is a great deal better than when we last tried the car. The enclosed chart shows the amount of understeering. It can be seen how the reduction of 5 lbs./sq.in. pressure in the front tyre considerably increases understeering. With the bumper fitted we think the worst feature on the car is now the riding, particularly that of the rear seats. This may be party due to our dampers, at the rear, but I should be inclined to blame the pressure velocity increase of the front dampers. Over a large ridge too much harshness is felt, although on wavy roads the car has a tendency for pitching. Unfortunately the Derby weather was bad whilst the car was here, so that we were unable to continue the readings on the chart., up to .5 g. {Mr Griffiths - Chief Accountant / Mr Gnapp} Very often cars change from understeering to oversteering near the limit. At the moment we have not got figures for a standard Bentley, but we do not expect them to be as good as the figures taken from your car. Mr. Robotham is interested in your hydraulic dampers, but is not in favour with the orifice for restriction. On more than one occasion we have tried to use orifice dampers owing to their simplicity and quietness, but we have always had to revert to spring loaded valves in order to dampen the slow movement of pitching without causing harshness on a bad ridge. | ||