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 Borg & Beck Ltd. regarding the development, testing, and material specifications for various clutches.
| Identifier | ExFiles\Box 129\3\ scan0027 | |
| Date | 8th January 1936 | |
| X110 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Smth.20/KW. 8th January, 1936. Messrs. Borg & Beck Ltd., Tachbrook Road, Leamington Spa. For the attention of Mr. Barker. Dear Sirs, We thank you for your letters of the 4th and 6th inst., and note that you have arranged to despatch 12 production clutches with the modified balancing and weaker thrust springs at the earliest possible moment. You will appreciate that we are very anxious not to hold up the Works programme any more than is absolutely necessary. We are proceeding with our development work on the 11" clutch applied to the 20/25 HP. chassis. Meanwhile, as in the case of our other cars, we are anxious to keep the pedal pressure down and should like to try some weaker thrust springs. It appears to us that your green springs (105 - 115 lbs.) should be adequate for the work, these giving a /u of .200. We should like your comments on this. We have once more gone into the possibility of there being some extraordinary feature in the test bed unit on which the 10" clutches broke which would account for the failure, but can find none. We are assured by the fitters that the clutch was properly balanced on the flywheel in each case. We note that you find our Ph.III pressure plate to be made of 14 ton material, and are investigating the discrepancy between this and the figure we gave you for the strength of Millenite. | ||