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).
Endurance testing and spring specifications for the 10' Borg & Beck clutch on a Bentley.
| Identifier | ExFiles\Box 129\3\ scan0011 | |
| Date | 3rd January 1936 | |
| X1100 To E.{Mr Elliott - Chief Engineer} H.{Arthur M. Hanbury - Head Complaints} By.{R.W. Bailey - Chief Engineer} c.c. to Roy.{Sir Henry Royce} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}16/KW.3.1.36. 10" Borg & Beck Clutch for the Bentley. The high speed endurance we have carried out on the test bed has indicated that it is important that the pressure plate should be balanced independently from the cover on the 10" clutch. We have therefore asked Messrs. Borg & Beck to withdraw the clutches they have supplied and correct them for pressure plate balance. At the same time we are asking them to revert to the original clutch springs which we used during the 10,000 miles test and which have been used in every other test we have subsequently carried out on Porlock, etc. These springs are 147 to 155 lbs. and are painted brown. The clutches delivered which are going to be taken back are fitted with 180 to 190 lbs. springs, which are red. We have examined the clutch off Hancock's car which ran with the weaker springs, and find it is in perfect condition. The objection to the heavier spring is that it puts up the pedal pressure and in our tests we have not found it to be necessary. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||