Bicycle Mechanics - threads are no good on my bottom bracket, but i must save this bike

I have a used Motobecane from the late 70s, i think. it has been riding well for three years, but after a small accident the bottom bracket has become very loose. I took it to the shop and they cannot seem to find a new bracket that will screw in tight enough... the frame looked like it could be re tapped to fit a new bracket, or just held in by some jb weld...the loosness wasnt that bad really and I could still ride around on it alright.

this is worth fixing to me, bc i cant afford a new frame right now, and because i like this frame a lot. and the bike just means a lot to me

so my question is... how can i hold this bracket in place?
will it be safe?

already tried teflon tape...
23" frame...
beautiful gorgeous gold frame, with lots of miles and memories...

thanks for any help

They can't find a bracket 'cause it's probably french threaded. French threads are very slightly larger diameter than a "standard" british threaded BB and are a finer thread.

Your options are either to find a french BB (35mmX1mm) or get a BB that screws into itself.

http://www.sheldonbrown.com/bbsize.html

I doubt it is french, since the drive side cup on a french bike is screwed in the oposite direction as a british bike. Maybe swiss?

might have to go with Italian threading.

or get a BB that screws into itself.

http://www.sheldonbrown.com/bbsize.html

For exmaple the YST "Threadless" bb, this will save your bike, but the bb is of ultra **** quality. No jokes.

My old French frame was retapped Italian and I use a 2mm spacer for the extra width.

I think that a late 70's Motobecane will have Swiss BB threads and I'll bet that someone used British cups. A Phil Wood BB and Swiss rings will save it, but figure about $140. You can watch eBay for a set of Swiss cups and maybe get them for $50. Swiss bottom brackets are the rarest of them all. You can find a shop that will retap the shell to Italian size and use an Italian BB with a 2mm spacer. I have no idea what that would cost.

You have to decide if it's worth it:
http://cgi.ebay.com/Vintage-Campagnolo-Nuovo-Record-Swiss-Bottom-Bracket_W0QQitemZ230261693986QQcmdZViewItem?hash=item230261693986&_trkparms=72%3A552%7C39%3A1%7C65%3A12&_trksid=p3286.c0.m14

I think that a late 70's Motobecane will have Swiss BB threads and I'll bet that someone used British cups. A Phil Wood BB and Swiss rings will save it, but figure about $140. You can watch eBay for a set of Swiss cups and maybe get them for $50. Swiss bottom brackets are the rarest of them all. You can find a shop that will retap the shell to Italian size and use an Italian BB with a 2mm spacer. I have no idea what that would cost.

You have to decide if it's worth it:
http://cgi.ebay.com/Vintage-Campagnolo-Nuovo-Record-Swiss-Bottom-Bracket_W0QQitemZ230261693986QQcmdZViewItem?hash=item230261693986&_trkparms=72%3A552%7C39%3A1%7C65%3A12&_trksid=p3286.c0.m14

I'd just retap to italian, it couldn't cost more than $50 to do it at your LBS and now you have a world of options in italian bb's.

Ill get some estimates and try to have it re tapped at another shop
thanks for all the help :)
ill let you know how it goes

one other thing... will my crank and pedals fit onto an italian bracket? I believe they're stock...
if not, is there a way to modify them to fit?
thanks again

one other thing... will my crank and pedals fit onto an italian bracket? I believe they're stock...
if not, is there a way to modify them to fit?
thanks again

crank will fit - basically it doesn't care about the BB shell threading. But you will have to find a new BB with the correct spindle length. You'll need to measure the length of the one you have now.

I think that a late 70's Motobecane will have Swiss BB threads and I'll bet that someone used British cups.


I don't know about that. My 1979 Team Champion is French threaded. Will the re-threading to Italian work with French threads, or is that just a recommendation based on the assumption that the threads are Swiss?