Originally Posted by
galenthas
I searched the local bike shops for a solution to no success. They are mostly salesman, no real bike mechanic in my town (at least to my knowledge). Actually, i looked at the solutions from velo-orange for their threadless bb yet, there is no fit for 45 mm.
I believe someone has done it before, I mean convert a similar size threadless bb in to a modern bb system (may be welding or threading involved).
Ok, let me ask like that, what would you do if you destroyed your favorite bike's threads in your 45mm diameter bb?
a.Try to fit a narrower shell (welding)?
b.Get it re-threaded?
c.Look for spare frame with threaded bb shell and integrate it to your frame? (cutting and stuff)
d.Look for an adapter of some sorts that may do the trick?
There are two approaches i can think of but neither are particularly cheap:
1. Have bushing rings made up with English threaded interior diameters and an OD matching the bb shell and braze them into the current shell after facing it down to 68 mm width. This is a variation on your options a and d. Don't even consider having a replacement shell welded to the old frame.
2. Buy a new English threaded frame and build it up with a current style bottom bracket and crank and transfer as many parts to it from the old bike as you can.
If you manage to "modernize" you current bb shell, you will need a new bottom bracket and crank in any event.