Originally Posted by
neurocop
The old school way to fix ruined BB threads is to rethread them with a BB thread tap. They are available in various sizes and are not cheap.
The most common way to salvage a damaged English, French or Swiss bottom bracket shell is to tap it ovesize to Italian threads.
I've heard mixed reports about those YSY bottom brackets' durability but they are cheap enough that keeping a spare or two on hand doesn't tie up a bunch of money.