[innergel]

How can I determine what the widest tire I can put on a rim is? Assuming that there is plenty of clearance in the frame, is there some sort of ratio I can use, is it stamped on the rim, or what?

I am building up a SS/fixie and the wheels have Mavic MA3 rims, so I'm curious as to what the largest size tires will fit.

 

[CycloPathic]

usually the opposite is the problem: you can't put narrow tire on wide rim or risk pintch flat. That's why many tandem FAQ tell you to use at least 28-32-35mm on T-520 or Dyad. With MA3 you shouldn't have any problems, whatever you can find that fits frame/fork. Look at MTB tire/rim ratio, and many MTB and road rims are the same.