How much room do you have? Are you running fenders? From experience I can tell you 38mm tires will just fit under Planet Bike 'hybrid' size fenders,42's won't. SKS and Civia have fenders that will fit them,but not too many bikes have clearance for those fenders.
Also,JMHO,but with tires that wide,I'd opt for folding bead if available. Never hurts to shave a little rotational weight.
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C'dale BBU('05 and '09)/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes,Giant Defy 1,Schwinn DBX SuperSport,Brompton S6L/S2E-X/M6L-X/S12 T Line
