if you have a compass that locks (like the geared ones, then i would use that, and set tit to the internal diameter of the headtube at one point just by opening it up until it is fairly tight , and spin it to check for gaps, and dents, but that is just one way, i am sure initiative should kick in to help you, also pay attention to lightly in my last post, as well as outer ring
if you have a compass that locks (like the geared ones, then i would use that, and set tit to the internal diameter of the headtube at one point just by opening it up until it is fairly tight , and spin it to check for gaps, and dents, but that is just one way, i am sure initiative should kick in to help you, also pay attention to lightly in my last post, as well as outer ring
only need to be small bends, but you can use a ruler if you want, i was just giving quite an easy method, even using the cartridge, because it is tapered, if you look from underneath/above you may see bulges in the cup