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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).
Abnormal clutch fabric wear on the 40/50 model during testing in France.

Identifier  ExFiles\Box 13\7\  07-page126
Date  20th June 1932
  
X 300

From Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}
c. to
c. to Hs.{Lord Ernest Hives - Chair}

Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}1/KT. 20.6.32.

Re. 40/50 CLUTCH.

We have experienced abnormal wear of the clutch fabrics on 19-EX during the 7,000 miles run in France. There are two possible reasons for this. Firstly, the power of the engine has been increased 15% with no alteration to the spring load on the clutch. Secondly, we have introduced the synchro-mesh gearbox which makes it possible to change gear from 3rd. to direct without releasing the throttle, thus causing excessive slipping of the clutch whilst taking up the drive. We have dismantled the clutch and have found that the steel plate has formed waves on the friction surface. The appearance is of the steel having been picked up and then rolled over leaving ridges crosswise. With the formation of these ridges the fabric is quickly rubbed off and the clutch pedal fouls the foot board. To overcome this trouble the spring load of the clutch is to be increased for further tests in France. The results will be reported.

In case of wear still taking place, it will be a question of altering the design.

Re. the 25 HP. car fitted with the synchromesh. We did not observe any undue wear of the clutch fabrics during the 10,000 miles test, but it is quite possible that this trouble may arise with the 25 HP. as with the Phantom.

Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}
  
  


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