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Vaginatarian
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Discussion Starter · #1 ·
my chain broke and it dreailled into my bottom bracket frame leaving a small 1/8" hole.
my question is what is the best way to repair it?
I have outboard bearings so water getting inside, while not the best is prob. not much of an issue. I'm thinking no welding as I dont want any warpage, maybe aluminum solder, epoxy clay, or silicone caulking. I'm a little nervous about the solder or epoxy not being real water tight. Its a Specialized enduro so there really isnt any other way for water to get in or out
 

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EDR
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10,312 Posts
dan0 - I would use 'JBWeld' if it were my bike. If you are not familair with it then......

it's a two part 'epoxy'. Epoxy is not really the right word. This stuff cures very hard and is PERMANANT! it is used for a million things. Mostly where you want to fill holes on metal of many kinds. It can be used to fill cracks in engine blocks, or as the name states, as a 'weld' without having to actually use a welder. Great stuff. Fill the hole, wipe off the extra and i'm sure it will be fixed for life. I would maybe pull the bottom bracket out so I could be sure the epoxy filled the hole but doesn't leak down into the bb shell. Basically fill it up and wipe both the inside and outside of the shell clean. -good luck

EDIT: you can find it at most auto parts stores or home improvement/hardware type stores.
 

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yeah, that's quite a derail to gauge a hole in the BB!
isn't this what duct tape is for?
silicone will work fine, but if you want to paint it, the 2-part sandable epoxy is the way to go.
dan0 said:
my chain broke and it dreailled into my bottom bracket frame leaving a small 1/8" hole.
my question is what is the best way to repair it?
I have outboard bearings so water getting inside, while not the best is prob. not much of an issue. I'm thinking no welding as I dont want any warpage, maybe aluminum solder, epoxy clay, or silicone caulking. I'm a little nervous about the solder or epoxy not being real water tight. Its a Specialized enduro so there really isnt any other way for water to get in or out
 

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Vaginatarian
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5,685 Posts
Discussion Starter · #4 ·
logbiter said:
yeah, that's quite a derail to gauge a hole in the BB!
isn't this what duct tape is for?
silicone will work fine, but if you want to paint it, the 2-part sandable epoxy is the way to go.
yeah I was going through a sand pit, I think I damaged the chain earlier, but the soft sand was hard to pedal so I was really cranking, suddenly the crank stopped dead, I looked and noticed the chain dragging behind, had to pull 3 links to repair. I didnt notice the hole untill I cleaned the bike a couple of days later. now I know how a chain saw works
I'm mostly trying to keep water and mud out of the shell.I think Ill try the stuff mentioned above, hopefully it makes a water tight seal
 

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Don't worry from water...

dan0 said:
yeah I was going through a sand pit, I think I damaged the chain earlier, but the soft sand was hard to pedal so I was really cranking, suddenly the crank stopped dead, I looked and noticed the chain dragging behind, had to pull 3 links to repair. I didnt notice the hole untill I cleaned the bike a couple of days later. now I know how a chain saw works
I'm mostly trying to keep water and mud out of the shell.I think Ill try the stuff mentioned above, hopefully it makes a water tight seal
drill another 3 mm hole in the bottom of the BB shell so they won't stay.
 

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Another vote for J-B Weld!

dan0 said:
I'm mostly trying to keep water and mud out of the shell.I think Ill try the stuff mentioned above, hopefully it makes a water tight seal
J-B Weld is good stuff. If you do it right, it'll definitely make a water tight seal. IMO, the trick to a successful J-B Weld job is surface preparation. Make sure that the area of the BB shell to which you're applying the J-B Weld is completely free of grease and oil. The J-B Weld web site recommends acetone or lacquer thinner for surface preparation. Solvents which might leave a petroleum residue should not be used.
 
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