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).
Suspension problems, specifically 'pitching' in the 40/50 HP model, and the ideal weight distribution for minimizing it.
| Identifier | ExFiles\Box 67a\2\ scan0079 | |
| Date | 20th December 1927 | |
| To Hm.{Capt. W. Hallam - Head Repairs} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} SUSPENSION 40/50. We are aware that one of the most difficult problems encountered by outside inspectors at the moment is that of suspension. We are continually working on this subject and consider that it may be of some assistance if we indicate the conclusions we have so far formed. We believe that the feature of any suspension system that causes greatest discomfort to the occupants of a car is that of 'pitching'. The 40/50 HP. pitches inherently more than the 20 HP. and that is why its riding is inferior to that of the smaller car. We believe that 'pitching' is not a question of spring strengths or type of spring employed, but mainly of weight distribution. The ideal system for absence of pitching can be illustrated by a dumbel with a spring under each end. This system when acted upon through the springs by a vertical external force will have the minimum tendency to pitch, a fact that can be proved mathematically. [Diagram showing two wheels connected by an axle with springs underneath each wheel. Labels: WHEELBASE, C OF G.{Mr Griffiths - Chief Accountant / Mr Gnapp}] Therefore an ideal car from the pitching point of view would be one with little weight in the centre of the wheel base and the maximum amount of weight each end. The car which conforms most nearly to these ideal conditions is the Lancia. The equivalent of the front axle is carried at the forward end of the sprung weight, the engine and gearbox are concentrated right forward under the bonnet, the contd :- | ||