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 to Cadillac discussing frame stiffness, sending test results, and asking for an opinion on cross-member positioning.
| Identifier | ExFiles\Box 170\2\ img290 | |
| Date | 27th August 1935 | |
| Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}16/KW. 27th August, 1935. M.{Mr Moon / Mr Moore} Olley, Esq., c/o.{Mr Oldham} The Cadillac Motor Co., Detroit, Michigan, U.S.A. Dear Cy., Rn.{Mr Robinson} gave me your letter about frame stiffness. I'm afraid I have been a long time in replying. We have always taken our figures by applying a pure torque at the front of the frame and measuring at various points down the chassis the angular twist by means of a finely divided level, resting on bars laid across the frame. I am sending you all the results we have so far obtained. We have only just got our apparatus rigged up for twisting stiff complete cars, which explains why the figures for the complete Cadillac and SpectreCodename for Phantom III are not very informative. We also have not taken hysteresis curves. Unless the friction varies with load, the difference between readings other than at the beginning should give the frame stiffness. Although not stated, the graphs we send you allow for this. There is one point on which we think you might be able to help us. If you have unit construction as on the V.16 the front of the cross will not be so far forward as with our type of cross which is made possible with a separate gearbox. Do you consider the position of our cross better than yours? Secondly, since the complete car is almost 10 times as stiff as the bare frame, is it any advantage to have a cross totally within the frame? | ||