In the 1930s Technical trials, there were bonus points for drum brakes - useful on mountain descents on gravel, where you can't just "let the bike roll," because the next turn won't allow you to brake hard.
So after that, many randonneur bikes had rear drums. In the 1940s, the emphasis on light weight made them a little less popular, but there still were quite a few bikes so equipped.
Don't know about the spacing. Maxi made both the cup-and-cone Maxi and the annular bearing Maxi-Car models, with up to three drum diameters (single, loaded single, tandem or something like that). Check out the camping Herse from 1948 in our book "The Golden Age of Handbuilt Bicycles." It has a Maxi drum brake and no other rear brake.
There were other manufacturers, at least before the war, such as Ideal and others. Some even made front drum brake hubs, but these were less popular.
Jan Heine, Seattle Editor/Publisher Vintage Bicycle Quarterly c/o Il Vecchio Bicycles 140 Lakeside Ave, Ste. C Seattle WA 98122 http://www.vintagebicyclepress.com
>A friend in Paris sent me some photos of a rusty 1940's 650B randonneur
>It has a center-pull brake mounted on brake bosses on the fork, and no brake
>bosses on the back.
>The brake bridge, on the seat stays, is drilled vertically, probably for a
>fender mount only.
>It looks as if the frame was designed for a rear drum brake as it has a
>braze-on loop on the underside of the left chainstay (to hold the arm on a
>Were drum brakes common on high end touring bikes back then?
>Who made them besides Maxi-Car?
>Were they wider than standard hubs?
>Did any maker or constructeur use such hubs regularly?
>Am I missing something?