Joined: Jun 2010
Posts: 2,136
Likes: 1,524
From: Medford MA
Bikes: Ron Cooper touring, 1959 Jack Taylor 650b ladyback touring tandem, Vitus 979, Joe Bell painted Claud Butler Dalesman, Colin Laing curved tube tandem, heavily-Dilberted 1982 Trek 6xx, René Herse tandem
There are two four ways I might go about this. All could be used in parallel.
1) Drill a small hole at the end of the crack so that it doesn't propagate farther.
2) Screw in a good quality BB cup with some strong epoxy like J-B Weld or Loctite Epoxy Weld or Araldite 2011 all over the threads, and just never take it out again. This would shore up the area rather well, I think. If the bike ever fully broke, you could heat it up and liberate the cup without damaging it.
3) Fabricate a "corset" to hold the BB shell together. I'd make a split ring out of steel or aluminum and have it bolt together like a seat post clamp.
4) Just ride it, but monitor it regularly. The trouble getting worse should first manifest by the cup unscrewing (if Italian, right-hand threaded) or shifting/clunking (feeling like a loose BB bearing), I'd think. I bet it will be pretty obvious before anything catastrophic is at risk to occur.
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Owner & co-founder, Cycles René Hubris. Unfortunately attaching questionable braze-ons to perfectly good frames since about 2015. With style.
Last edited by scarlson; 05-22-21 at 09:48 AM.