Just to seed the discussion and provoke more messages..... In the early fifties, you could have used a Sturmey Archer hub gear with a two or three speed Cyclo derailleur and probably a two speed Witmy derailleir with a Sturmey K before the war. I am told that Cyclo offered Rosa double chain wheels with quite wide differences. I believe that they did 48/30 in the late forties. That could give a range from the mid thirties up to about ninety. I asked a while ago on this list what range the more common derailleurs of thirties to early fifties could cope with; no replies, unfortunately. Anybody care to comment now. It would be nice to have an old bike set up woth contemporary equipment for touring. And by old I mean before the Queen's Coronation! Stuart Tallack surrounded by obsolete everything in West Sussex