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Help cross threading in bb shell

hat and beard

Maximum Pace
Apr 3, 2012
437
516
Preface: I'm an idiot :oops:

It seems I have crossed the threads on the non drive side of my bottom bracket shell.:cry: I remember it going in pretty smoothly, and I definitely installed it in the correct direction, but I just noticed today that the cup(correct term?) wasn't sitting in the shell straight. bb.jpg
I've been riding it for a month now and can't believe I haven't noticed this before. I have felt a slight vibration coming through the pedals when I'm pedaling in a high gear or hard into a headwind, which is what got me to take a second look at the bottom bracket. Other than that no problems. There is no detectable play in the cranks if I try pulling them side to side.

So... What now? It's come to my attention that Velo Orange makes a threadless bottom bracket for just these kinds of problems. No suppliers in Japan seem to carry it however. Any other makers make something similar? Any better options? Advice much appreciated.
Frame is steel. Bottom bracket is 68 mm JIS square taper.
 
Erm, are you sure it is cross threaded?

Have you taken it out and examined the threads in the BB shell?

Prey that the threads are fine, and this is just a case of the face of the BB shell not being straight.

If the threads are gashed up, you can certainly see about tapping them straight before you start messing around with alternative BBs
 
Yes, I took it out and I can see where the threads have been crossed.

Putting it back in it installs normally until about half way, jumps a little, and then keeps going in at a different angle.
 
Gotcha.

Any chance you can shine a torch into the BB shell, and then take a photo so we can see the extend of the mangling?
 
After a second look I'm less sure now. What looked like mangled thread to me was just grease. The threads look a little gnarly where the chain stay tubing meets the BB shell, but I can't tell for certain if anything is crossed.
Unfortunately I'm having trouble taking a picture that looks like anything. I'm going to take it to the guy who built the frame tomorrow and see what he can do.
Thanks for your help @TCC
 
Perhaps ream and reweld another tube inside the shell and re tap that.
 
Tap it, then face and chase.
If your local dealer is decent, they should be able to clean up the threads if the damage isnt too bad.

If its repairable, I say 10-20 minutes max, and Y3000-5000....maybe much cheaper.
 
Isn't that a custom frame?
It should have been faced & Chased.
Kind of hard to think it would not be.
 
Homeboy was able to re-tap the threads. I have no idea how I managed to get it in like that in the first place. I think my days as a bike mechanic are over.
This is indeed a once in a life time never gonna spend this kind of money on a bike again sold my right arm for it custom frame, so I freaked out a bit when I noticed this. All is well now.
 
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