Jack Hoobin, Amateur World Road Race champion 1950
I think the distinction has to be drawn that it was the Amateur worlds that Jack Hoobin won, much closer in status to the current U-23 race than the elite RR. This was in the day of the very strict interpretation of "Amateur", all he would have had to do is accept a five quid prize once in his life and he wouldn't have been eligible.
Still to race and win in Belgium while not being able to accept prize money or sponsorship dollars shows quite a bucketload of dedication.
If anyone knows more about Hoobin I'd be curious to hear. I know he raced at the Olympics in '48 and I believe he raced against Mockbridge and Patterson but I don't actually know any more than that.