Can't Remove Crank Arm

Haydn1

Hi, I was trying to remove my cranks to install a new BB and found that the drive side crank will not come off with the crank puller. The crank puller just pushes itself away from the bike leaving the crank in place, I think it is because the threads in the crank arm are worn.

Is there anything else I can try to remove it? Short of sawing through it and getting a replacement?

Thanks a lot
Haydn

Matthewfalle

What kind of b/b? What kind of crank arms (carbon or Ali?)

Anyhow, one particularly ungraceful method on square taper and Octalink is to get a drift and hammer and from the opposite (ie non drive side) poke the drift through to where the crank arm attaches to the b/b and smack it - if you go in a circular motion it will ease the crank arm off without too much damage.

frisbee

A bit of heat might help.

Bearing puller if you have access you one or make up something that hooks around the spider/rings.

k-dog

Do you have the right adapter in it?

I had to get a new one a few years ago because the old one had a smaller threaded part and wasn't pushing against anything.

Monty Dog

Sounds like a square taper, ISIS or Octalink type BB given the need for a crank-puller - try a fork-type ball-joint splitter and a big hammer or a two-prong bearing puller. FWIW threads for crank pullers have been pretty standard since the 80s - oddities include some old Stronglight and Campagnolo with lefthand threads

keef66

You sure you haven't left a washer behind when you removed the crank bolt? I did that once and it stopped the crank puller screwing in properly / fully.

Matthewfalle

Or is the crank puller all ok - the funny ball end bit fell off the end of my Octalink one and I didn't notice for an attempt - same thing happened when trying to get the crank off (ie puller just came out sans crank).

mamba80

well if you ve pulled the threads out of the crank arm, even if you did manage to get it of in one piece you d only have the same issues next time round, so hacksaw, heat and a hammer are your friends.
if its shimano octalink, you need a small circular piece of metal that goes between the axle and the end of the crank puller.
its called a shimano octalink chainset plug tool and CRC have them @ 4.99

fast as fupp

heat it up with a blowlamp-(carefully)- the aluminium of the crank will expand more than the steel axle- it should fall off then.

trust me ive done this.

Haydn1

It is a square taper bottom bracket & the crank is alu, so ill try heating and hammering. But i suppose Ill probably need to get a new crank arm too.

Thanks a lot for the advice

k-dog wrote:

Do you have the right adapter in it?

I think it happened originally because the crank puller I was using has a larger surface detachable pin on the end which i forgot to remove, so it was pushing against the crank rather than the BB. oops

pinarellokid

I had this issue this week on a friends bike we ended up cutting through the BB and then drifting the small bit out of the chainset. Easier to do than heat and the BB was knackered anyway

DeVlaeminck

Have ou tried screwing the crank puller in again. If it wasn't screwed far enough in that it pulled out there may be enough thread left to have another go - this happened tome the first time I used one years ago.

If not in order I'd try the mallet from other side, ride round and see if it comes loose, heat tricks. Seeing as it may well be buggered anyway you may as well reuse the crank you can always hacksaw it off if you have to in future.

Matthewfalle

Or just retap the thread in the crank arm and do it again - literally a 5 minute job to retap.