replacing a nervex bb shell

[Alexi]

I *may* have to replace the bb shell on my 1950's track bike. Is this a stupid idea? would it be prohitively expensive?

[Dave Moulton]

A quick and dirty BB repair that works. Assuming a stripped thread is your problem. Remove BB spindle and cups. Hold the frame upside down in a vise and cut a slot across the BB shell on the stripped side. Use a hacksaw with two blades fitted side by side. Hammer the slot closed and weld with an arc welder or TIG welder. This usually doesn’t burn too much paint and can be touched up with a brush. It doesn’t show underneath anyway. What you have done is to make the inside diameter smaller. The BB thread can now be re-tapped. Your LBS should be able to do that for you.