Originally Posted by
europa
rt's syndrome complicated with the top half of a bottle of red.
I can't see how anyone would be happy with a crack circling any tube, unless one could be sure it's only in the paint (and hence a warning of horrors to come). Fuggit, rather than me just being rude and completely missing the point, could you explain this again in different terms because there's something that I'm not understanding the way you do.
The real danger is a) the head tube coming off, or b) the head tube splitting open and your fork falling out.
Option A is cracks at the joints between frame tubes, B is a vertical crack.
So if it's just a crack circling the tube, not going through the lugs in any way, it doesn't really matter all too much. At this point, you've now got two head tubes stacked one on top of the other, squished closed by your headset and steerer tube.
It'd probably creak like buggery, invite rust, and look awful, but it's not going to suddenly fail under you unless you're getting ten feet of air or something.