stuck bottom bracket...

[bigdawg]

Im sure this has come up time and time again, but ivedone a search and still cant find it...

Ive got a 94 zaskar frame with the original bottom bracket, whcih seems to be welded in place...

what are the tips and trick for getting these things out - Ive tried inititally soaking it and then applied the ball breaker - 3 1/2 foot socket wrench - didnt even think about moving...!

any tips hints would be hugely appreciated...

 

[hamster]

Let's start with the daft question first, as a process of elimination: You are turning it the right way?

Lots of plus-gas for about a week is often needed to free things, and possibly a bit of heat shock (pour boiling water over it) as at least you have the Alu on the outside, so it should expand away from the steel BB thread.

 

[craiga]

Are you definitely turning the correct way? English or Italian thread? Are there arrows on the bracket?

If that's OK people put penetrating oil inside the frame through drinks holder holes & then turn it on the side to soak in.

Then try in a vice & move the frame for increased leverage.

Having said that you should have enough leverage on a 3 foor + wrench.

So it's back to soaking in oil / Gt85 etc & checking

Good Luck

 

[bigdawg]

thanks guys - yep it is the right direction, I was using the cups from an old bb to check -Il give it another week of soaking and then may consider force injecting grease in there as tbh I think its usable, just needs grease on the bearings..

 

[Splatter Paint]

Try boiling water on the BB shell after penetrating oil has been applied, wrap a towel around the shell to retain the heat.

Non-drive side: undo normal (anticlockwise)
Drive-side: left hand thread (undo clockwise)

If you invert the bike, double check you're doing it the right way, I have spent a fair while trying to do a BB up

Try undoing the drive side instead of the non-drive first. A bolt through the tool body into the axle will prevent slipping of the tool.

SP

 

[bigdawg]

Try boiling water on the BB shell after penetrating oil has been applied, wrap a towel around the shell to retain the heat.

Non-drive side: undo normal (anticlockwise)
Drive-side: left hand thread (undo clockwise)

If you invert the bike, double check you're doing it the right way, I have spent a fair while trying to do a BB up

Try undoing the drive side instead of the non-drive first. A bolt through the tool body into the axle will prevent slipping of the tool.

SP

why havent I thought of that in the past nearly 20 years of building bikes..?!

great tip...

 

[djoptix]

If you strip the splines, the last resort (which will pretty much work on any BB no matter how badly threaded it is) is to find a friend with a welder. Weld a big nut onto the bit that's left in the frame. Clamp the big nut in a vice and rotate the frame around it.

Be aware that the ground wire may cause marking on the metal so it's best to clamp it to a rear dropout where it will be covered by the QR.

 

[02gf74]

^^^ what they say.

use a scriber or other pointy item to break rust seat between the frame and cups then use penetraiting fluid - the proper swtuff e.g. Plus Gas not wd40 or gt85.

you can make a little cup e.g. from plasticine or tape and plastic over the BB when bike is horizontal to keep the fluid in place - note the fluid may disolve the glue on the tape.

leave it for a while then do similar but with fluid from inside the tube via the seat tube.

then use a breaker bar and pull/push on it so it is in tension and give it a whack with a rubber mallet to shock the BB or try using an air gun.

it may be an idea to put hte BB removal tool in a bench vice and turn the frame as it is very easy for the tool/bar to slip. (note: make sure you turn the right way!!)

if this fails, then you can try heat - boiling water isn't gonna cut it so you need to go for a blow torch - you can get a fair bit of heat in before the paint starts to spoil - maybe you have to accept the paint will be damaged and carry on heating but don't go too crazy if the frame is brazed or heat treated aluminium.

another option is to smash the cups out - these are hardened steel so a chisel and hammer should do it - never had to do that myself.

remember RH - chainset side is LH thread.

good luck - let us know how you get on.

PS I have windy gun so if you are local, bring your frame over.

 

[djoptix]

Plus Gas is indeed the shizzle. Just don't spill it over anything complex (like an engine) - it''ll dismantle itself over a period of weeks

 

[Splatter Paint]

Boiling water does help, but yes, generally more heat is required. I've used a hot-air (paint stripper) gun as this doesn't have a naked flame, but you will damage the paint if you're not careful.

SP