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).
Performance of the 11' Borg & Beck clutch on the 20/25 HP model and recommending against its immediate production.
| Identifier | ExFiles\Box 129\3\ scan0007 | |
| Date | 2nd January 1936 | |
| X1110 To E.{Mr Elliott - Chief Engineer} & By.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}S/KW.2.1.36. Big Bore 20/25 HP. Clutches. As a result of further experience on the 11" Borg & Beck clutch on the 20/25, we have decided we are not yet ready to go into production with this. We had about 9 months' running on this clutch on the Bentley, when it gave perfectly satisfactory results. We have, however, had only 2 such clutches on the 20/25 - one on Sg{Arthur F. Sidgreaves - MD}'s car, which he is not satisfied with; and one on 21-G-IV, which also does not give a sufficiently smooth take-up. We explain this by the fact that the 20/25 is more sensitive to clutch smoothness, owing to its Terraplane type of engine mounting. We think there is no doubt that the 11" Borg and Beck clutch can be made satisfactory by attention to the facing material, of which we are not using the best for smooth engagement, and also the cushioning of the centre plate, but this will require a certain amount of experimental work. We were particularly anxious to fit this clutch in view of the considerable saving in cost but under existing conditions are forced to recommend that we continue with the standard type of pre big bore clutch and flywheel until we have carried out further work. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||