Originally Posted by
achoo
The bottom bracket threads aren't structural?
Of course they are.
All those thread do is hold the crankset while you're hammering away on the pedals. They're taking a LOT of stress when they're doing that.
Yup. And even the heat from the MAPP gas torch will compromise the frame's heat treatment and strength in that area. The bottom bracket is the most complex joint on the frame -- four tubes come together there. Compromising the heat treatment in that area is not something I'd advise.