Originally Posted by 3alarmer

I worked on a low end bike at the coop that puzzled the hell out of me
until I figured out the BB shell was ovalized. Old school loose bearing BB.

Guy was having trouble adjusting it after removing the adjustable cup
and cleaning and regreasing. I figure it had crap in the threads, so
ran the taps through it. Still the same problem, too tight to adjust
well.

When you run the taps through they force it out round again and that's
the shape as you chase or cut new threads. Not a problem, because you
have the tap handles and all that leverage. As soon as you remove
them, it springs back to oval, so you cannot adjust the bearing play
worth a damn.

But this one was a lower end bike that probably came that way from
the maker. I honestly don't see how you can ovalize a BB shell by
riding it.......wouldn't the cups kinda work against that ?

since you are using external bearing crank, I think you ought to be
OK with just putting in new bearings/cups, since you don't need to make
bearing adjustments......anyway, that's what I'd try, too.

if that does not work, you can either try a standard sealed bearing
unit in the BB, with the appropriate crank for it, or one of those
threadless things they sell at Velo Orange.

I sure wouldn't go with the frame repair except as a last resort.