Front Der clamp frame tolerances
 

I'll keep this short, what are acceptable tolerances for front der clamps? My frame, after finishing, is 32.4, I assume that is within reason for a 31.8 braze on clamp? I don't have many options if not....

Shimano lists +/- .5mm as the tolerance, so you should be okay

It's easy to make a shim to take up the difference. Easier then making a "negative" one:) . Andy

shim wouldn't work, he would need to remove some metal. Which probably isn't a bad idea. Some of these have a locating bump, that would have to go. But he's only out .3mm, so should be within tolerance.

Yeah, I got that, the OP's issue, backwards although my comments are otherwise correct. Andy