Should take 35 mm.
Cantilever were dia compe.
I have a load of cantilever brakes, from mafac tandem or normal. Dia Compe, and the more low profile type of cantilever. And some magura fluid ones unused. Many years of cycling.
I've always liked Roberts frames, top quality builder, attention to detail. Met him one time at York rally, exceptionally nice bloke and 100% passionate about bikes
