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).
Experiments on vehicle body attachments and frame damping.
| Identifier | ExFiles\Box 14\8\ Scan220 | |
| Date | 19th February 1930 guessed | |
| -5- (c) As a further parallel experiment we tried with and without spare wheels in the side position. Carrying the spare wheels at the side made a definite improvement. Altering the Body Attachment. (a) "With the standard sub-frame mounting we found that by coupling the dash very tightly to the body (without removing the sorbo rubber strip between the two) we were able to use the body to damp the frame movement. The effect of this damping was increased by stiffening up the front of the frame with tubular cross members designed by W.W. in front and behind the radiator. (b) We have carried out various tests with the sub-frame single point mounted at the front and rear but so far have no results that could justify proceeding with such an awkward arrangement, which incidentally is liable to spoil the steering of the car due to the body heeling over on corners. Our previous results quoted by Ev.{Ivan Evernden - coachwork} were obtained with the cross in the frame. (c) We proved that various types of bodies produce various degrees of damping owing to their different moments of inertia, rigidity, etc. Thus the front of a "Cabriolet de Ville" has little or no torsional stiffness and will follow the dash on the least provocation once the car has been knocked about on bad roads. The damping in this case is obtained in the joints of the body rather than between the scuttle and dash. Also the fact that the body is so weak torsionally forward of the partition makes the frame periodicity somewhat different | ||