Stuck for a full day on a seized bottom bracket in a steel frame

Had a 90s steel road bike come in with a square taper bottom bracket that would not budge, even with my longest breaker bar and a ton of penetrating oil. I ended up building a jig to hold the frame and using a 4-foot pipe on the tool, which finally broke it free after about 8 hours of trying different things. What's your go-to method for a bracket that's really stuck in there?

3 comments

3 Comments

seanlee3d ago

Honestly, I've had the best luck with a big pipe on the breaker bar and a solid hit with a mallet to shock it loose before applying steady pressure. The key is making sure the frame can't twist, so I'll clamp the down tube in a bench vise with soft jaws. If that fails, heat is the next step, but you gotta be real careful with a steel frame to not wreck the paint. Sometimes it just takes a mix of patience, more penetrating oil, and a lot of force.

anna_ross1912d ago

Been there... my last resort is always heat. I get a propane torch and carefully heat the shell of the bottom bracket, not the tool, until it's really hot to the touch. The metal expands and breaks the rust bond. Then I hit it with my longest breaker bar while it's still hot. It usually pops right out, but you have to be careful not to damage the paint.

lane.cameron11d ago

That "last resort" heat trick is a lifesaver. I've had a few bottom brackets that just would not budge until I broke out the torch. It feels so good when it finally lets go.