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).
Technical discussion comparing Girling brakes with the company's own floating fulcrum brake system, considering costs, weight, and performance.
| Identifier | ExFiles\Box 92\4\ scan0217 | |
| Date | 30th September 1936 guessed | |
| (sheet 2) which on the first page of the report Rm{William Robotham - Chief Engineer} says we shall not use. It is, therefore, extremely doubtful if we should be able to achieve the saving shewn for the complete Girling system, and at the same time we should be taking on a change in brake technique, of which we have very little experience. Our first experiment with the Girling brakes in their original floating fulcrum form gave disappointing results, and resulted in the system being condemned by the Experimental department at that time. We know that the floating fulcrum brake is not as good as our own in being more sensitive to changes in coefficient of friction due to water etc, having less capacity for wear by its concentration on one brake shoe. The latest Girling scheme however we understand is fitted with a pivot and link mechanism somewhat similar to the Rolls-Royce brake shoe operation which practically converts the brake into a fixed fulcrum type. We should like to know if this extra mechanism is included in the quoted costs for the Girling brake. On this question of costs it might be as well to point out that we have not had great success with buying outside, one example of which is the Stromberg carburetter, apart from the question of the constant trouble involved in obtaining satisfactory parts from the suppliers. With regard to the question of weight, the Bentley III and Wraith scheme dispenses with the hand brake, and like Phantom uses equalisers of the Girling type. The only difference then lies in the brake shoes, operation and adjustment. In these last named we should anticipate being a little heavier, but here we would point out that our method of adjustment does not interfere with the brake shoe bedding, whereas that fitted to the Girling does, and is, therefore, liable to seriously alter the brake characteristics. A point I have omitted to mention with regard to the experimental scheme is that as shown the hand brake operation is illegal as the snapping of the rear cable would deprive the car entirely of brakes. Some extra mechanism would, therefore, be required which would add to the cost figures already given for this scheme. | ||