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. requesting information on the coefficient of friction for 'Hycoe' clutch material.
| Identifier | ExFiles\Box 129\1\ scan0008 | |
| Date | 10th September 1936 | |
| X1110 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Smth.14/KW. 10th September, 1936. Messrs. Borg & Beck Ltd., Tachbrook Road, Leamington Spa. For the attention of Mr. Barker. Dear Sirs, We are now fitting the 10" driven plate faced with English "Hycoe" to a chassis. Since we do not know what working coefficient of friction is permissible with Hycoe, we are starting the test by using stronger springs (cream ones in a 10A6 clutch). Have you any information concerning the comparative u/'s of Hycoe and ordinary moulded material ? We have learned to distrust figures obtained in a friction machine, and are anxious to know what u/ is actually practicable in service. For instance, Ferodo "No.6" appears to require about 15% more spring pressure than moulded material although its u/ seems to be only about 3% lower when determined in a testing machine. It would be a point very much in favour of Hycoe if we could use it on the Bentley and retain the present spring pressure. If you have no information available at the moment, possibly you could obtain some for us from the Long people in America. Presumably the name of the material is meant to imply that its u/ is higher than is usually obtained with rubber base fabrics. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||