converting old schwinn with ashtabula BB to a cartridge BB
Not sure about a cartridge BB, but you can convert it to square-taper to allow different crank choices:
Add a Conversion piece, it's 2 machined rings, that are pulled together with 3 or 4 bolts,
and the rings are threaded, and there is the shoulder on the rings that holds them in place..
For installing screw in BBs.. Any Bike shop should have a source for one..
Insane Bicycle Mechanic
Any bike shop in the U.S. should be able to order this:
Originally Posted by fietsbob
or something similar.