Stuck external BB.... ideas?

Big molgrips.

I tend to soak in plusgas overnight. Wheels off bike. Tool in vice and turn the bike.

Bolt the tool onto the cup to reduce chance of it slipping off 

Last resort cut it out carefully.

I know it should be obvious but, definitely turning it the right way?

I know it should be obvious but, definitely turning it the right way?

Clockwise as you look at it, the opposite way to the "tighten" arrow.

How would you bolt a cup to a BB?

Like this?

Well thats what I don't want to achieve.....

Pour boiling water over it. Differential expansion might free the corrosion. 

You can use a long bolt with a couple of washers. Might get a headset press through depending on the tool. Don't overtighten it, just enough to stop the tool slipping off the splines.

I bolt the tool on.
Soak with whatever penetrant you can possibly find.
Use boiling water over frame, keeping off the BB if you can. Do this a few times for it to heat up and cool down - then last time move very quickly from applying heat to leverage....
....from the main strut of my old bike stand (about 1.5m long) popped over the handle of adjustable wrench plus a 'volunteer' standing on the frame while I apply as much body weight as needed on the lever...

Clamp the BB in a vise and turn the frame.

Ice worked for me with a gxp bb and ti frame

Do you have access to those 'Stilson' self gripping wrenches?

I don’t have any of those tools so hot water it’ll be…

Diesel as a soaking penetrant is totally awesome.

I also second heat too.

Whats the frame made of?

Diesel as a soaking penetrant is totally awesome.

My dad was taught to use diesel mixed with paraffin when we worked on a farm back in the day. Not sure why but it works.

I think Park Tool do a (pricey) gadget that holds everything together to stop the BB tool slipping. LBS might have one of those?

Clamp the BB in a vise and turn the frame.

That is what I did a few years ago and worked a treat. There is a a lot of leverage from frame and a lot of grip on BB from vice so not surprising it works really.

scotroutes Full Member
Pour boiling water over it. Differential expansion might free the corrosion.

This. I did it the other day with a BB scotroutes Full Member sold me 11 years ago.

Edit: Pour it over the BB shell of the frame, not the cup. You want the frame hole to get bigger. You could jam a Calippo or similar in the BB cup to make that smaller

@nedrapier - are you about to ask for a refund?

New bike.

You know it makes sense

I am another who has clamped a stuck BB in a vice and turned the frame.

Don't do ny more unless you can clamp the tool in. Washers etc.

If its moved a couple of mm then can you work it back and forth?   Heat and penetrating oil as well

@Jimmy did you have to chisel that out in the end?

I removed a stuck outboard bearing bottom bracket by knocking out the bearings with a hammer and cold chisel. Then using a hacksaw (you can remove the blade and then refit it through the bottom brack), I carefully cut a couple of slots into it. I then just knocked it out with the hammer and chisel. It took a while but the bike was unharmed. 

Take it to a bike shop who will clamp via tool in the vice and turn the frame. They did that for a ceased shimano traditional BB for me. Nominal charge as it came out fine.

I bodged this together to solve a similar problem.

@suspendedanimation - kind of. The idea was to saw the outer cup into sections and knock it to release the threads, which worked but the hacksaw went through the cup like butter, and the frame unfortunately.

It's worth putting pressure on it alternately clockwise and anticlockwise to break the corrosion, I find it works better than just turning to undo.

This is a good place to remind folk that turbo trainer bikes collect a lot of salt damage. Check those stem bolts etc while you're at it. Remove, clean and regrease regularly. And if you have aluminium handlebars, check they're not corroding beneath the bar tape.

Big Stillson is my goto tool for stuck external cups. Works a treat

Make a thing like what Sixtoes had done.

Boiling water won't be enough heat so if it's a metal frame use a wallpaper stripper heat gun until you hear a sort of popping noise (no idea what that does to CTO carbon, not tried it) then use the gadget you built but you should be able to stand on the lever. If your tool won't let you out a breaker bar on it see if you can slip a bit of scaffold pipe or something over the end of it to make it longer.

And then show.me how the formatting on here works

Remove the bearings first, worked for me.