Adjustable bottom bracket cup stuck fast. Any tips?

[Cyclopathic]

It's the type with the two flats that offer very little purchase. On top of that it's an aliminium frame and I fear that it is coroded on. I've squazzed it with penetrating oil but to no avail and I'm all out of ideas. This stupid heat isn't helping my efforts or my mood either so any ideas welcome.

 

[TheDoctor]

Is that the side with a reverse thread?
If so, get a nut and bolt that'll go through the hole where the spindle used to be.
Feed the bolt through, put the nut on and start tightening it with a big long spanner.
The direction to tighten the nut should be the direction that'll loosen the cup, and it's easier to apply more force this way.
Alternatively, hold the cup in a vice and use the frame as a lever to get it turning.

 

[Cyclopathic]

Is that the side with a reverse thread?
If so, get a nut and bolt that'll go through the hole where the spindle used to be.
Feed the bolt through, put the nut on and start tightening it with a big long spanner.
The direction to tighten the nut should be the direction that'll loosen the cup, and it's easier to apply more force this way.
Alternatively, hold the cup in a vice and use the frame as a lever to get it turning.

It's the normal thread side. That is a flippin good tip though. I saw an illustration of it on Sheldon Brown's site when I was researching this problem and was much impressed. I'm almost looking forward to trying it out one day. Almost.
I've tried putting it in a vice but the flats are sooooo shallow that there is no purchace to be had. I am probably going to have to weld a sturdy piece of steel on to the cup to use as leverage. Just need a welder now.

 

[compo]

Obvious point but just make sure that the nut and bolt is big enough to take the force required without stripping it's threads. You want the nut or the bolt head big enough to just fit inside the cup.

 

[tyred]

5/8" bolt is the biggest you can probably use for most bb cups but it won't work on the normal threaded side.

If you have a quality tool which is a good fit on the flats of the cup, you could use a bolt and a large washer to hold it in place while you try to unscrew it, similar to what you might do to unscrew a freewheel block by using the axle nut to hold the removal tool in place.

Try and find a friendly garage who will braze a large nut to the outside of the cup. The temperatures will be lower than for welding. Try this at your own risk as the heat may still damage an alloy frame. Ideally it would be done with the whole frame under water with only the end of the BB shell sticking out.

 

[steve52]

find a left handed nut and bolt,

 

[Tim Hall]

find a left handed nut and bolt,

No, a standard nut and bolt will do it. Bolt head on the inside, nut on the outside. Tighten the bolt, rather than the nut and Bob's your wossnmame. Linky

 

[02GF74]

No, a standard nut and bolt will do it. Bolt head on the inside, nut on the outside. Tighten the bolt, rather than the nut and Bob's your wossnmame. Linky

won't make any difference whcih way round you put the bolt/nut - as you tighten the bolt, so you will tighten the cup. you need left hand threaded bolt/nut as thingy said.

...... back to OP question; use penetrating fluid e.g. plusgas (not wd40) from both sides - also you can try warming up the bottom bracket or use a dremel to cut the cup as long as you are you not to damage the frame.

 

[Tim Hall]

won't make any difference whcih way round you put the bolt/nut - as you tighten the bolt, so you will tighten the cup. you need left hand threaded bolt/nut as thingy said.

I'd say you're "differently correct". The bolt tightens against the nut, and at the same time squeezes against the BB cup. The tightening of the bolt (right hand thread) is the loosening of the cup (left hand thread) Have you read the link? Or tried it in Real Life?

...... back to OP question; use penetrating fluid e.g. plusgas (not wd40) from both sides - also you can try warming up the bottom bracket or use a dremel to cut the cup as long as you are you not to damage the frame.

I'm with you on the superiority of Plus Gas over WD40.

 

[RecordAceFromNew]

It's the type with the two flats that offer very little purchase.

It's the normal thread side.

I know variations are possible but the adjustable cup with flats on the "normal thread" side, i.e. the LEFT side, usually has a lock ring right? and once the lock ring has been loosened the flat bit is like pic below, which ime can usually be removed without too much trouble, by either the special tool shown or even the smaller "U" on Raleigh's fab "multitool" further down that used to come with all their bikes.

So just to confirm is the above cup hard to shift after the lock ring is out? What tool have you been using?

On the other hand the RIGHT side is generally the fixed cup and for British thread bb e.g. is reverse threaded, for which a spanner on the flats shown below is generally a waste of time, and Sheldon's nut and bolt method is best, in conjunction with a BIG spanner. Ensuring beforehand bb is not Italian or French threaded first, obviously...

Just checking, like.

 

[Cyclopathic]

As it happens both the adjustable and non adjustable cup are fairly well stuck and the axle is still in but your idea is a sound one for the next time this happens and I can get access to it. I probably wouldn't have thought of simply reversing the process like this to take off the adjustable side as I don't have any left hand threaded bolts of the right size (or any size) but what I do have near by is an excellent shop that specialise in selling nuts and bolts and fastenings. They have come through for me before when I've needed something out of the ordinary so I will task them once again with providing me with a left threaded bolt and some nuts.
I was so pleased with their service the last time they helped me I bought them some chocolate hobnobs.

 

[smokeysmoo]

Clamp in a vice and use the leverage of the entire frame to move it.

This is how I've got them out in the past.

 

[02GF74]

I'd say you're "differently correct". The bolt tightens against the nut, and at the same time squeezes against the BB cup. The tightening of the bolt (right hand thread) is the loosening of the cup (left hand thread) Have you read the link? Or tried it in Real Life?

No I did not read the link. I accept that when a RH threaded bolt is tightened in a LH cup (chainring side), once the bolt is fully tightened, any more torque will result in either the bolt shearing off or the LH cup unscrewing.

Using RH threaded bolt in a RH cup, to undo the cup the bolt needs to turned anti-clockwise which is more than likely to unsrew the bolt instead of the cup.

 

[Rickshaw Phil]

Using RH threaded bolt in a RH cup, to undo the cup the bolt needs to turned anti-clockwise which is more than likely to unsrew the bolt instead of the cup.

Yes, but if done the way Tim suggested; tightening the bolt from the inside of the BB shell - IE clockwise as viewed from the right hand side of the bike, the torque will be applied anti-clockwise as viewed from the left side of the bike, thereby undoing the LH BB cup.

Makes good sense if the RH cup is already out.

 

[02GF74]

yep - you're right - I missed the bit about putting bolt from the other side of the cup.