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 faults of four-wheel brakes on two cars after 3000 miles of testing in France.
| Identifier | Morton\M20.3\ img022 | |
| Date | 6th June 1924 | |
| EXPERIMENTAL REPORT. REF: Hs{Lord Ernest Hives - Chair}3/LGA.6.6.24. Expl. No. 9940 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. RO.{C. C. Rose - Export Manager} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to EY. WOR.{Arthur Wormald - General Works Manager} FOUR WHEEL BRAKES. S E C R E T. The two cars which are running in France with the adopted scheme of brakes had completed on Friday the 13th. inst, approximately 3000 miles on each car. The brakes are behaving very well. As both cars have worn out the rear tyres, the brakes must have been severely tested, so far as the brakes have not been touched. The tests have shewn up the following faults :- (1) The thump which is caused by the servo taking up the clearance in the front brakes very rapidly is manifest on the cars even when fitted with the 'Halo' type liner for the servo. The thump is influenced by the strength of the pull off springs on the front brakes and the state of the adjustment or the amount of slack on the front brakes. Owing to the front brakes being controlled only by the servo, it will be realised that it may be difficult to positively overcome this complaint. If we stiffen up the pull off springs on the front brakes we can reduce it but what is left comes in at a later period of the brake pedal. Some cars appear to be free from it but we have been able to produce it on any car if we introduce the maximum amount of slack in the front brakes. (2) Both cars have complained of jaggers after running in France. Before the cars went away, we turned off the stiffening web and made the dust cover to suit, we still contd:- | ||