[CR]D.Granger's Hobb's cranks-dureel?

(Example: Racing:Roger de Vlaeminck)

From: Seth F. <mozzi-3@att.net>
To: classicrendezvous@bikelist.org
Date: Sun, 23 Apr 2006 20:41:37 +0000
Subject: [CR]D.Granger's Hobb's cranks-dureel?

Hi Folks:
   Duncan Granger shared his very British-of-a-certain-age Hobbs with us in some yahoo pix.The distinctive chainwheel on that would be the Williams "dureel",which I've only seen in drawings.My question to people of old local knowledge is if that name means dural rings on steel arms,and,just how short was the production life of those critters?
     Thanks a lot,hopefully,
        Seth Finkelstein,Santa Cruz,CA