can anyone recommend a u-brake that would have clearance for 26*2.1 with mudguard
Two months late ... Try a pair of Suntour Roller Cam? I have 559x50 tyres on my tandem, the brakes can clear the mudguard if you set the cam height just right. Tyres need to be deflated to remove wheel though.
can anyone recommend a u-brake that would have clearance for 26*2.1 with mudguard