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Cold Welded Bb Cups


Jonny Jones

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Hi people

OK, Ive been given this bike to 'clean up' for my neibour and he wants a new BB put in. Slight problem, both cups are cold welded in! They simply wont turn.

Its an old old old steel racing kinda bike, open bearings, old skool cups - Driveside has flat sides where you put a large spanner and the non driveside has nothing but a ridge down the center to put some kind of gay tool that i dont have, even in my Park Tool Advanced Toolkit.

gallery_3624_1027_22532.jpg

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As I say, cold welded, any advice on getting that bast***s out?

Cheers!

Jonny.

Edited by trialmedia
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Well once chemical metal has set.. There's no way of unsetting it :shifty:

Heat it up with a blow torch and g'it some pasty with a long pole and the spanner? Would ruin the paint work though.

Why has it been set in though ;) The cups are suposed to be greased before they go in!!

Edited by Sam@SouthTrials
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Well once chemical metal has set.. There's no way of unsetting it  :shifty:

Heat it up with a blow torch and g'it some pasty with a screwdriver and a hammer? Would ruin the paint work though.

Why has it been set in though ;)

Steel can fuse to steel chemically it's called a cold weld.

Seriously, try to shock it free, hit the end of the axle with a hammer, the vibrations can break the chemical bond.

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Yeah I would but a blow torch to it. It expands the metal and softens it slightly. If its a steel frame then you definatly wont have a problem after.

Blow torch all the way round it then try again as soon as you stop.

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Haha, I know nobody who works at a garage

You know me Jonny........

I would just use brute force and Ignorance.

Try and get the frame in a vice, and use a Big hammer and chisel on the Non drive side ridge, and if you have the right spanner, you may have to beat the crap out of it to get it out.

If not, just tell your neigbour, it cant be done

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You know me Jonny........

I would just use brute force and Ignorance.

Try and get the frame in a vice, and use a Big hammer and chisel on the Non drive side ridge, and if you have the right spanner, you may have to beat the crap out of it to get it out.

If not, just tell your neigbour, it cant be done

True I do know you Lee (Y)

Ive tried pretty much everything. The long pole thing wont work cos the spanner is pretty wide so theres nowt that can go on the end of it.

I may just say, scrap it, get a new bike.

J.

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Surely the spanner can't be wider than the shell - axle length?

Just get some spacers of any kind and the old crank bolt and use them to hold the spanner tight to the bb shell and then muscle it off with a long lever or a hammer for some shock.

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i've had loads of experience with this exact problem, there really isn't much you can do or worth doing, the design is really poo, because you cant put mucho pressur on the spanner 'cos it slips off, i would leave it in and say `tiss not woth it :) (Y)

Edited by rhythm_101
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gallery_3624_1027_56322.jpg

the bit you put the spanner around.... put that into a vice, make sure its TIGGGGHT! get someone to push down on the frame to help it not slip out , then turn the frame!

surely it cant slip in the vice, the BB would shatter before you brake the vice. but if it does, atleast you no it was never ment to come out!

Trust, it will work! i would do it for you if i lived closer!

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Bolt a big adjustable onto the drive side using the bb axle and washers then undo anticlockwise. When you have the drive side out shove the axel in and to the same with the adjustable on the non drive side. 16mm should be the right size for the non drive side.

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