While it appears that some of the Paris-based cycleframe builders were able to carry on much as usual, the same could not be said of others in other parts of France.
I read in an article recently that Andre Reiss, the builder of the renowned REYHAND frames, was arrested by the German army in the early 1940s, possibly in 1940 itself, deported and shot. There again there were very odd goings on in the region of Vichy and Lyon during the war, and large pockets of the Resistance or Maquis were based in these areas and were very active against the Germans.
On the other hand there were many French who collaborated with the Germans eg the Vichy Government of Free France set up by Marshall Petain in July 1940, some of whose leaders were eventually executed after the War ended, for war crimes.
Norris Lockley
Settle UK