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 Messrs. Ferodo Ltd. regarding the testing of Thermoid brake liners and issues with squeaking.
| Identifier | ExFiles\Box 140\4\ scan0081 | |
| Date | 15th November 1937 | |
| 1180 Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}10/NH. Messrs. Ferodo Ltd., Chapel-en-le-Frith. 15th. November 1937. Your Ref. JNL/KM. For the attention of Mr.Longley. Dear Sirs, In reply to your letter of 13th. inst. When we have carried out further testing on the Thermoid liners we will tell you the number of the lining we like. We would prefer that you obtained the Making Particulars of this lining rather than have you make up samples from a guess at the constituents of it, as this might well involve us in unnecessary work and expenditure. In ordering, we quoted a coefficient of friction (0.33) and specifically mentioned that we wanted freedom from squeaks. We attribute thefreedom from squeak on American cars to the fact that they use American linings. When we reline our American test cars with English made linings, they start to squeal at once. The Thermoid linings we have squeal very lightly when dead cold, otherwise they do not squeal. This represents an enormous advance over anything else we have tried. | ||