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).
Technical memorandum comparing two types of Phantom clutches and their associated performance issues.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan068 | |
| Date | 15th September 1930 | |
| TO R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wox. c. to Z. De. c. to Ev.{Ivan Evernden - coachwork} ORIGINAL 8 x7480 y7305 PHANTOM CLUTCH. The more tests we do comparing the two types of clutches, the more we are convinced that it would be safer to stick to the present clutch with the improvements than to go to the new one with the fabric on the driven member. The Ferodo people, who deal with a tremendous lot of clutch problems and in many cases design clutches for different firms, prefer the fabric on the pressure plates. They say there have been quite a number of successful clutches made with the fabric on the driven member but there is no outstanding advantage in this construction. In our opinion, the reason why the Americans would go for this is because it can be made in a cheaper form. Our troubles, when we have the fabric on the driven member are that if we slip a clutch excessively the pressure plate jams on the splines; this has occurred even when we have doubled the clearance. When this happens it is most disconcerting because it is impossible to free the clutch or to drive the car. The only thing to do is to wait until it cools down and then it will behave perfectly normal again. Since we have doubled the clearance on the pressure plate, we then get the clutch dragging badly if one attempts | ||