Help! taking the Crank off the BB

andyanansu said:

I'm trying to take this crank off the BB from my old bike
the bike has been in the garden battle with rain and shine for around 2 years
so most of the components has gone rusty :eek:
I've taken the cap and 14mm screw off the crank arm
and I've put some oil between the Crank and BB
it's not rusty inside, but I just can't extract it 😠
any suggestions please!
Andy

Assuming you did not leave a washer in the crankarm hole, turn harder conterclockwise.You coud also try the boiling water over the crankarm trick.

boudreaux said:

Assuming you did not leave a washer in the crankarm hole, turn harder conterclockwise.You coud also try the boiling water over the crankarm trick.

Mine crank arm haven't got washer under the 14mm bolt, it looks like they're both intergrated.
and I think is not turning conterclockwise? but the other way round.
can you give a bit more details about that 'boiling water' trick please?
thanks

andyanansu said:

Mine crank arm haven't got washer under the 14mm bolt, it looks like they're both intergrated.
and I think is not turning conterclockwise? but the other way round.
can you give a bit more details about that 'boiling water' trick please?
thanks

Yeah,right on that counterclockwise,that's to remove the fixing bolt ...sorry.

It sounds obvious but no mention is made of a crank extractor after you have removed the bolt?

PiledHigher said:

It sounds obvious but no mention is made of a crank extractor after you have removed the bolt?

Yes, I use the extractor to remove both, but only manage to get the bolt off only.
Can you help?

After the boilts are out the crank extractor screws into the thread in the crank to push the cranks off (assuming a square taper not a splined bottom bracket)

PiledHigher said:

After the boilts are out the crank extractor screws into the thread in the crank to push the cranks off (assuming a square taper not a splined bottom bracket)

yes it's a square type, I understand how the extractor works
I even tried to hammer the crank out, but without success.
the square bit on the crank is too tight
I might have to try to saw the crank off now.

I would suggest alot of penetrating fluid, something like WD-40 or Triflow. Allow ample time for the fluid to find it's way into the gap.

Then I would cycle around to try and 'loosen' the the cranks off the spindles.

Finally use the crack puller and try your luck, becareful not to damage the threads on the crank arm.

andyanansu said:

yes it's a square type, I understand how the extractor works
I even tried to hammer the crank out, but without success.
the square bit on the crank is too tight
I might have to try to saw the crank off now.

I'd try heat to expand the aluminum end around the taper like boudreaux suggest. Either boiling water, an electric heat gun, big soldering iron, or careful use of a propane torch.

I've seen an air impact extractor tool used as well.

Andy - is there any chance you can post a digital picture of the problem?

Aggro Bikes said:

Andy - is there any chance you can post a digital picture of the problem?

homepage.ntlworld.comCrankLeft.jpgOpen ↗
homepage.ntlworld.comCrankRight.jpgOpen ↗
See the pics 🙂
and please help 🙁

Ok- I just went through the thread again, and can't see a reason for it, so I have to ask:

Is there a reason you aren't using one of these to pull it off? Or, are you, and it just isn't working? I don't care how frozen that thing is- with some penetrating oil and by using an extractor, it should come off.

*Note* Before I get accused of it, I am not shamelessly promoting our website with that link... you should be able to find one in your local bike shop.

andyanansu said:

homepage.ntlworld.comCrankLeft.jpgOpen ↗
homepage.ntlworld.comCrankRight.jpgOpen ↗
See the pics 🙂
and please help 🙁

Have you tried the heat yet? If you can heat the aluminum to around 200-250*F without heating up the BB axle, bet it will come off easily for you.

Aggro Bikes said:

Is there a reason you aren't using one of these to pull it off? Or, are you, and it just isn't working? I don't care how frozen that thing is- with some penetrating oil and by using an extractor, it should come off.

I'm using one of these, not the exact same one on the pic, but similar:
unicycle.co.nzView.phpOpen ↗

dhk said:

Have you tried the heat yet? If you can heat the aluminum to around 200-250*F without heating up the BB axle, bet it will come off easily for you.

I'll try the heat method tomorrow morning.
how come heating it make it easier?
the metal should expand when heated shouldn't it? 😕

andyanansu said:

I'm using one of these, not the exact same one on the pic, but similar:
unicycle.co.nzView.phpOpen ↗

I'll try the heat method tomorrow morning.
how come heating it make it easier?
the metal should expand when heated shouldn't it? 😕

Aluminum expands more than steel. I've never had a problem getting even the gnarliest cranks off a tapered spindle.Just how hard are you turning and how long is the wrench handle?

Ive Always found that the crank will expand with heat and depending on the material and thickness you may find the size of the square hole in the crank will shrink while the spindle in the b/b will expand
Therefore try the opposite, throw the whole thing in a big freezer (ive used a trunk freezer) and this usually does the trick.

Phreak
UK