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).
Internal memorandum evaluating the advantages and disadvantages of the Farnsworth spring suspension system.
| Identifier | ExFiles\Box 154\1\ scan0031 | |
| Date | 1st November 1929 | |
| WOR{Arthur Wormald - General Works Manager} THE FARNSWORTH SPRING SUSPENSION. Referring to the above matter which I regret I have been unable to deal with earlier, due to pressure of our own problems, the position is as follows :- RECEIVED In the first place, I cannot subscribe to anything like Mr. Farnsworth's written views of its virtues. It has, of course, certain advantages, but at the same time it has certain serious debits, the latter being such as to put it out of court so far as this Company is concerned. The advantages of the system are that it undoubtedly reduces the unsprung mass, and therefore compels the road wheels controlled by it to follow the road surface more closely than would be the case in the design generally used. This undoubtedly reduces the tendency of the wheel to skid by maintaining a more regular pressure between the tyre and the road, which is all to the good in preventing conditions being set up by spring effects which may result in skidding, both as regards front and rear wheels. The front suspension also gives greater lateral rigidity, and thereby tends to prevent wheel wobble, as absence of lateral elasticity will effectually prevent a wobble from attaining serious dimensions, although it will not prevent incipient wobble effects from being present :- The defects of the system are :- a/- Front suspension. 1/- The 'fore and aft' inclination of the pivot pin varies through very large angles, which in itself must result in steering instability. 2/- The application of the system is undoubtedly extremely difficult, as the cross shafts controlling the wheels must pass beneath the engine. This is a very serious debit in designs, calling for low built chassis with normal engine design. 3/- There is a distinct effect with the normal cross steering tube for the steering road wheels to run as on average out of line, thereby wearing the tyres. This could be overcome, but would entail a very complicated design to put this matter right. b/- Rear suspension. 1/- There is a very serious debit due to the | ||