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).
The performance and standardisation of a new M.R. brake material on the 20/25 Chassis and Bentley models.
| Identifier | ExFiles\Box 102\3\ scan0114 | |
| Date | 20th June 1933 | |
| Brake Material. We recently standardised M.R. material on the 20/25 Chassis commencing at B.2 series. This is the same material as is fitted to the Bentley. The chief reason for adopting this material was to increase the life of the linings and prevent scoring of the drums. This material was fitted to 18-G-IV's last 10,000 miles test. We find in GWH{George W. Hancock - Head Chateauroux}'s report at 15,000 miles dated 20.6.33 from Chateauroux on examining the brakes at 7649 miles that "The material wore very little and was in good condition. The brake drums were exceptionally good". Standard lining was then fitted to the car - "This material has worn quicker and has produced bad ridges in the brake drum surfaces". In the previous test of 18-G-IV fitted with standard linings, all the chauffeur's adjustment had been used at 9500 miles. During the first Bentley test in France all the brake adjustment had been used at 14,000 miles. For the last test M.R.material was substituted instead of bonded asbestos. Only one fifth of the adjustment had been used after 10,000 miles. It is unfortunate that M.R. material is so adversely affected by water. It has undoubtedly very superior wearing qualities over the standard Bonded asbestos lining. We have asked JLE{J. Lee Evans - Chassis Test Manager} to let us know whether the present 20/25 cars suffer from inefficient brakes to the same extent as the Bentleys. His first impression of a few chassis was that they did not. We expect by now that he can give us an opinion of a considerable number of cars. | ||