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).
Unsatisfactory performance of direct-action brakes compared to servo-operated systems on various cars.
| Identifier | ExFiles\Box 179b\2\ img006 | |
| Date | 4th October 1932 | |
| ORIGINAL To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to CE. c. to TE. By.{R.W. Bailey - Chief Engineer} c. to Edy. BENSPORT BRAKES. We cannot quote any car with direct action brakes which we should look upon as satisfactory. The Alfa-Romeo car which we had, had very inferior brakes to any of our cars including the Peregrine. The 20 HP. Alvis sports car we tried the other day the brakes were quite impossible. On the Lanchester car which we have, if we disconnect the vacuum servo these brakes are no good. You will remember Mr. Grylls, Senior, owned a Bentley three litre then an Invicta and afterwards a 25 HP. R.R. The Invicta was a fast sporting car. It had large sized brakes and was a reasonably light car. The experience however was that after every long run the brakes had to be adjusted. There was always a risk of losing your brakes on a long descent. With the 25 HP. R.R. they did not adjust the brakes once. They believe they may have been looked at when the engine was decarbonised, but that was the only attention they received. E.{Mr Elliott - Chief Engineer} who has a Vauxhall with direct acting brakes is of the opinion that although the brakes on that car are better than most other cars with direct braking, they cannot be compared with servo operated brakes. Bentley tried for years to make four wheel brake cars with direct braking but he never got any really satisfactory results until they adopted a vacuum servo. Hs.{Lord Ernest Hives - Chair} | ||