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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).
Front brake effectiveness, steering faults, and brake rig testing.

Identifier  ExFiles\Box 30\6\  Scan146
Date  12th July 1923
  
R.R. 493A (40 H) (SL 42 12-7-23). J.H.,D.{John DeLooze - Company Secretary}
-4-
EXPERIMENTAL REPORT.
Expl. No. 9940
REF:Hs{Lord Ernest Hives - Chair}4/LG11.1.24.

the front brake is most effective, the car steers in that direction. On the cars we are running at the present time with four brakes, we should treat this as perhaps the worst fault.
On the std. EAC. we do not get true centre-point steering with the average dimensioned tyre. It is .250" off. We have however tried road wheels fitted with larger diameter tyres and also wheels fitted with the smallest diameter tyres. With these we can get from .460" to .160" off centre-point. We could not however overcome the faults. We have carefully measured up the Hispano and find it is .750" off centre-point. When we tried that car we confirmed that the steering was affected when braking but it may have been that the brakes happened to be equal. When the car is running again we propose making a special test with this. In order to prove that it was not due to the twisting of the front axle, we tried with a solid piece of wood fitted in place of the front springs. The effect was still the same. At the present time we are checking over the actual cars to see that the point of contact is where it is intended.

BRAKE TESTS ON THE RIG.

We have now an improved rig and have been carrying out a number of tests with standard front wheel brakes. A full report is being got out in connection with this. One difficulty at present is that the results on the rig do not agree with the results we obtain on the road, for instance, on the rig the Extex floating fulcrum brake is quite as efficient or slightly more so than the standard, yet, taking the actual brake off the rig and trying it on a car, we do not get the same results. contd:
  
  


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