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).
Brake and suspension tests, focusing on spring shackling, equaliser levers, and braking performance under various conditions for different models.
| Identifier | ExFiles\Box 84\2\ scan0130 | |
| Date | 22th March 1934 | |
| -2- RB{R. Bowen}/GRY.{Shadwell Grylls}10/KM.22.3.34. To overcome this and for other reasons we have on B.23.AE shackled the springs at the rear, the front half now being in tension instead of the rear half buckling under compression. It would be an advantage to increase the length of the levers in the front equaliser. At the moment the plate lever turns through such a large angle as almost to end in line with the pull rod from the balance lever - an inefficient state of affairs. On the 40/50 and 2/25 the line of pull of the rear brake ropes has always passed through the axle. On J-3 and the Bentley it is below the axle. We have carried out some interesting tests to show the effect of this. Both a 40/50 and J.3 were towed by another car after the rear brakes had been applied, with results as follow:- 40/50 forwards. Impossible to lock rear wheels by direct braking only. When servo helps the pedal moves down about half an inch and the wheels can be locked. 40/50 backwards. Exactly as above. J-3 forwards. The wheels can be locked with direct brakes only. As the axle twists the pedal does not move, but by watching the axle it is seen that the brakes are self-servoing. On a wet surface the lightest pressure will lock the wheels. J-3 backwards. As the axle twists the pedal goes down to the boards and the wheels cannot be locked. The twist of the rear axle of the J-3 type tends to take off the front brakes if there is any friction on the swinging arm, and also causes premature locking of the rear wheels. | ||