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).
Alterations to aluminium brake drums for the back brakes of Bentley cars.
| Identifier | ExFiles\Box 85\1\ scan0077 | |
| Date | 20th April 1936 | |
| BY: C.E. Ex. Ds. Rs.{Sir Henry Royce's Secretary} RMC. HS{Lord Ernest Hives - Chair}/Fm. Aluminium Brake Drums for Back Brakes. Bentley. We send herewith N.Sch.4796 which shows the above. In cases where these drums are fitted to existing hubs, the proportions shown by the scrap view should be used. The only alteration made in this case is a reduction of the spigot diameter, and a corresponding reduction of the outside diameter of the cone for the wheel hub. The main scheme has, in addition to the above spigot reduction, an increase of bolt circle diameter and of outside diameter of the flange. The object of these alterations is to obtain more metal in the drum between the bolts and the spigot. We understand that the increased outside diameter will clean up out of existing forgings. The oil catcher and holes which are at present provided on the drum should be retained in the form shown by the scrap view for E.R.Hall's car for Le Mans, but should be deleted for all our own experimental cars. We understand that it may be desired to fit a smaller rim than the one now standard, and in this case it appears that the rib nearest to the wheel will have to be reduced in diameter to clear the disc, but as we have no exact particulars we are not making any provision at this stage. E/HDY.{William Hardy} N.Sch.4796 herewith. | ||