Quick advice for removing bottom bracket pls - [Sorted]

[Erudin]

...Was thinking about then getting this to a tyre place so they can use a air rattle gun on it - it that a wise idea or just likely to cause damage?

I don't know the answer but R J The Bike Guy did a vid on it: https://youtu.be/SJ1qosxTGbY

[PH]

I use the Tacx BB tool, screws on so no chance of slipping
https://www.sjscycles.co.uk/tools/tacx- ... andard-m8/

[alexnharvey]

Can you apply lubricant while you wait for your bolt?

If the LH cup is removed you should be able to carefully pour a little lubricant to sit on that side. Even motor oil or other light oil (possibly with some solvent added) would potentially offer some benefit if you don't have a proper penetrating lube. Of course, some might also get into the downtube and chainstays.

I mentioned above that I have used a clamp to keep the tool in place in the past. Not as solid as a bolt or skewer but it offers some help keeping it engaged.

[NoIdea]

Can you apply lubricant while you wait for your bolt?

I can but I've had in depth discussions on this subject with a mechanical engineer and we cannot understand how a lubricant (or penetrative fluid) can possibly do anything to un-seize a fastener. Unless it can literally dissolve the corrosion I don't see how it will unstick and stuck fastener?

I mentioned above that I have used a clamp to keep the tool in place in the past. Not as solid as a bolt or skewer but it offers some help keeping it engaged.

I think we are past using a clamp, and also judging by teh amount of force we were putting into that BB I think we are past using human power and leverage. I think I'm going to need the shock/impact force that only an impact wrench can give.

[alexnharvey]

Proper penetrating oils have additives that do indeed address the corrosion, as will motor oil I believe. I don't see what you've got to lose by trying some lubricant, and maybe you and your engineer chum will learn something, after all there's plenty of scientific and anecdotal evidence that such penetrants do help, despite the conclusion of your in depth discussions.

Certainly impact is another thing you can try though.

Of course, it's your bike and your knuckles

[rjb]

have a look at this for inspiration or perspiration
viewtopic.php?f=5&t=94465&hilit=bottom+dawes
This one ended up in the recycling box. My tools were worth more than the frame to me.

[Gattonero]

....

I think we are past using a clamp, and also judging by teh amount of force we were putting into that BB I think we are past using human power and leverage. I think I'm going to need the shock/impact force that only an impact wrench can give.

I think you're simply using the wrong technique.
You will never remove it if the extractor is not firmly in place.

Fix that.
Remove the wheels, put the frame on the floor, one chap is holding the bars, the other one holds the saddle and with his foot will push a 20" spanner.

[NoIdea]

I think you're simply using the wrong technique.
You will never remove it if the extractor is not firmly in place.

Just to clarify our technique...

Bike was up on the bench but leant over slightly and supported/wedged in place.
I was holding the bike still, my mate was both pressing the tool in and cranking the 15" breaker bar.
It still popped out but he was putting in a hell of a lot of force.

I can try again once I have the correct bolt to lock the tool in place, as that will make the whole process easier..
The problem is I think we were getting to the point of exceeding the torque that a 15" bar is happy with.
I do a have a short alloy scaffold pole that can go over a different socket bar, and then it becomes a 4ft breaker bar... but I'm just worried what this is/could do to the frame. I think using a rattle gun will be less harmful to the frame, maybe?

[robgul]

Another angle : you can get a penetrating oil that freezes (literally) the metal and is pretty good at separating seized stuff.

It's called Chill Zone and is made by Finish Line ... loads of places sell it

From reading the thread it seems that it's a square taper BB and you have the LH positioning cup out already? Lay the frame on a bench, drive side down and spray the Chill Zone VERY LIBERALLY into the BB shell around the actual cartridge - wait 10 minutes and do it again, ditto a couple of times.

Then have another go with the BB tool (with a longish lever) - holding the frame in a decent workstand or in a vice (careful not to crush the tubes) will make a difference.

.... we see loads of "seized" BBs and have yet to fail to get one out - just need patience.

Rob

[NoIdea]

Proper penetrating oils have additives that do indeed address the corrosion, as will motor oil I believe.
Do you have any links that support this?
(Not taking the P, I'm very interested as I currently have zero faith in penetrating fluids to do anything other than lubrication the nut/bolt head and making it more likely to round off/out. Also I don't belive motor oil can do this, but will be happily surprised if it can.

I don't see what you've got to lose by trying some lubricant,
Oil getting on the BB key and encouraging it to slip/jump and round out, that's my fear. Just that it'll make a mess that I have to clean up afterwards... for no actual gain.

and maybe you and your engineer chum will learn something, after all there's plenty of scientific and anecdotal evidence that such penetrants do help, despite the conclusion of your in depth discussions.
Always happy to learn.
Now where is all this evidence?

Just out of interest, here is an extract from the thread rjb posted, a quote from Brucey.

"IME in this situation penetrating oils (cold) don't help all that much; the gap between the BB unit and the frame threads is already packed tight with (expanding) oxide debris."

Which is one of the arguments I proposed to my engineering buddy.
Even if the fluid could actually dissolve the oxidisation (which I don't think it can), I don't think it can even get to it!

[NoIdea]

Another angle : you can get a penetrating oil that freezes (literally) the metal and is pretty good at separating seized stuff.

It's called Chill Zone and is made by Finish Line ... loads of places sell it

I like the sound of that.

From reading the thread it seems that it's a square taper BB and you have the LH positioning cup out already?
That's correct, it was tight but was just a plastic one so wasn't able to seize in as firmly.

Lay the frame on a bench, drive side down and spray the Chill Zone VERY LIBERALLY into the BB shell around the actual cartridge - wait 10 minutes and do it again, ditto a couple of times.
Then have another go with the BB tool (with a longish lever).
Will do.

I'll get hold of some chill zone as well as the 8mm fine threaded bolt.

[alexnharvey]

I'd use heat and a penetrating lubricant. I'd use a syringe to squirt it into the NDS, so it wouldn't get on the splines. If any did I'd wipe it off.

I'd bolt or clamp the tool in place then grip the tool in a bench mounted vice, so I could use the frame as the lever. If using a breaker bar or scaffolding extension bar I'd go longer and apply less force at the end, I find I damage myself less that way than leaning heavily on a shorter bar.

I should've thought a bit more about the aluminium-steel aspect before getting a little snotty with my reply does seem like it might not help a great deal, or would take a very long time. I'd still be hoping it would at least begin to help as things started to move. Sorry and good luck.

[AndyA]

An impact wrench seems like a great idea, but it will likely bounce out of the splines. It can also break the splines on the tool.
If you bolt the tool securely and use a decent length lever it will move. I prefer to do it with the wheels on the bike, bike on it's wheels, tool bolted onto axle, bike held up by assistant (or adjustable height stand if you have), 6ft scaffold pole on spanner on tool.
You've got the non-drive side out already, great. Spray whatever lubricant you prefer in there, I don't think it matters too much which flavour.
Drive-side is reverse threaded, turn it clockwise to remove.
When it does move, prevent the Aluminium of the frame threads galling by working the BB clockwise 1/2 turn, anticlockwise 1/4 turn etc. An excess of oil/lube also help prevents galling aka stripping out the thread.
Good luck!

[SilverBadge]

Bench mounted vice.
Removal tool facing upwards
Frame lowered over tool
Frame used as lever arm.
Agree that heat/cold can help break corrosion, as can penetrants (anyone mentioned ammonia yet?)
Need a hole in the removal tool, then either crank bolt or studding right through to washer/nut on other side will secure splines in place.

[Brucey]

re the 'chill zone' stuff; any thermal shock can help to break the bonds of corrosion, but for a steel BB in an aluminium frame, the relative CTE values between aluminium and steel do not work in your favour; the colder the assembly gets, the tighter the steel cup is gripped by the aluminium shell. By contrast heating it up loosens its grip.

By contrast if there were an aluminium piece in a steel housing, cooling the assembly would be more helpful.

cheers