Did you get it like that ? Return it. That’s a mess.
Or did a gorilla have access to BB tools ?
Aggressive_Ad_5454 on
A bike shop may have a thread-tapping tool that can clean that up. You can ask.
Such a tool is a metal-cutter built to cut those exact threads. They aren’t cheap tools and they take some skill to use. But they work in the hands of a skilled craftsperson.
Cross-threading happens sometimes and causes this kind of thing. It’s fixable.
epicrdr on
If you have a competent bike shop they can fix that. I’ve had it done and it isn’t as hard as it seems. They just need to have the right tool.
WoofWoofster on
Looking at this picture, the bottom bracket shell looks like it’s never been faced or chased. Usually, a good bike shop selling a frame does both. I’d be upset with whoever or whatever sold you the frame.
As others have posted, a good bike shop should be able to chase the threads. (They should faced the BB shell first.)
Also, a goood framebuilder can do chase and face the bb shell.
did you try putting in a bb that isnt threaded that way?
sowhateveryonedoesit on
Cheap Chromoly frame? Tig weld some er80s filler, bore and chase the threads on a bridgeport. Hardest part will be tramming the frame on a temporary jig.
DenThomp on
That’s looks like a mighty large thread, the tap would be enormous. Might have been thread milled on a CNC?
7 Comments
Did you get it like that ? Return it. That’s a mess.
Or did a gorilla have access to BB tools ?
A bike shop may have a thread-tapping tool that can clean that up. You can ask.
Such a tool is a metal-cutter built to cut those exact threads. They aren’t cheap tools and they take some skill to use. But they work in the hands of a skilled craftsperson.
Cross-threading happens sometimes and causes this kind of thing. It’s fixable.
If you have a competent bike shop they can fix that. I’ve had it done and it isn’t as hard as it seems. They just need to have the right tool.
Looking at this picture, the bottom bracket shell looks like it’s never been faced or chased. Usually, a good bike shop selling a frame does both. I’d be upset with whoever or whatever sold you the frame.
As others have posted, a good bike shop should be able to chase the threads. (They should faced the BB shell first.)
Also, a goood framebuilder can do chase and face the bb shell.
Link to the Park Tools page on this. There are lots of pages and videos on these things elsewhere.
[https://www.parktool.com/en-us/blog/repair-help/bottom-bracket-tapping-threading-chasing-and-facing](https://www.parktool.com/en-us/blog/repair-help/bottom-bracket-tapping-threading-chasing-and-facing)
did you try putting in a bb that isnt threaded that way?
Cheap Chromoly frame? Tig weld some er80s filler, bore and chase the threads on a bridgeport. Hardest part will be tramming the frame on a temporary jig.
That’s looks like a mighty large thread, the tap would be enormous. Might have been thread milled on a CNC?