Originally Posted by
eddubal
It looks like you can create a collar reinforcement under your current seat binder. Bend a piece of metal around the seat tube under the collar, and attach it with it's own bolt under the current binder bolt. No welding necessary.
That's what I would think as well. The part of the seat tube extending above the top tube is not structural. One concern would be to prevent the crack from propagating further down into the weld area, which is structural. Drill the end of the crack to help prevent this, and keep a close eye on it to detect any tendency to extend the crack.