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).
Historical problems with subframe mounting and the justification for adding a central support.
| Identifier | ExFiles\Box 14\8\ Scan233 | |
| Date | 15th March 1930 | |
| X7380 TO HS{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} FROM EV.{Ivan Evernden - coachwork} EVI/15.3.30. COPY TO E.{Mr Elliott - Chief Engineer} RE SUBFRAME MOUNTING. P.2. We thank you for your HS{Lord Ernest Hives - Chair}/HMI/MJ.12.3.30. re the instructions for mounting a subframe body as given in our book. We do not agree that there is any difference between the instruction for mounting as given on N.Sch.2623. and the book. The former says:- " The body is put on the chassis resting on the main forward and centre supports.-------- The aft rubbers are then put into position and the packing filed until it can be driven in when the body is slightly eased up." The book, in paragraph 5. says exactly the same as this. Our original subframes had no centre support, the rear support being the main one. We had trouble with the scheme because the main chassis frame on P.I. did not like the main support of the body being on its cantilever rear ends and the frame of 7EX. broke. Another trouble was that the span of the subframe between its supports was too great. The direct deflexion vertically was sufficiently great on open cars and cabriolets to cause the doors to lose their adjustment very quickly. For this reason "H" instructed the additional centre support to be added to 7.EX. and 14.EX. The third trouble was that of the subframe bending transversely in the horizontal plane. This could be felt as a "jellying" when riding in the car. For all of these reasons "H" said let us put the main and solid support under the centre of mass of the body. He contended that this centre support should be a solid metal to metal joint | ||