Can anyone help? I have a well stuck square taper crank arm. The arm is aluminium, the bottom bracket spindle steel.

Being a retrobiker I have plenty of experience of removing these but this one has stumped me and already burst one tool with another well on the way.

I have so far tried a few kettles of boiling water over the spindle whilst under tension and tried whacking it with a hammer. Any other bright ideas?

Last ditch effort if the bb had it remove the opposite cup and center punch the spindle out.

not a nice fix but iv used it before.

Make sure that there isn’t a washer that was on the crank bolt stuck in the recess below the dust cap, preventing the crank puller from contacting the bottom bracket spindle. Sometimes these have a black finish and are hard to see…

Mini ball joint splitter?

Try refitting the bolt/nut and leave it loose a couple of turns and then just ride it but keep your eye on it.

With the pressure of pedalling, eventually it should loosen off enough to remove by hand.

There’s a good chance the taper will be knackered after though

HTH

PS

The taper could be knackered after though

stupid edit delay!!!!!

Bigger hammer.

You could cut through the spindle if you have time and can get access. Then bash out the remains from the crank and replace the BB.

Riding it around with the bolt loose has always worked eventually for me

Good tip from JoeG…….

I’ve had plenty of success with a blow torch. Heat the crank up a bit around the bolt hole. Tap with the hammer and off it comes.

Great puller to get a bit of tension and a hammer to loosen it off?

https://www.amazon.co.uk/Silverline-MS23-Gear-Puller-3-Piece/dp/B000LFVPYE/ref=mp_s_a_1_3?ie=UTF8&qid=1539631491&sr=8-3&pi=AC_SX236_SY340_FMwebp_QL65

I’ve had to cut one off before. It’s painful

Loctite freeze and release spray then used a good puller to put some tension on it a tap with hammer if it hasn’t popped off

Thanks all, few things to try for sure.

leave the bolt off and ride it around the block a few times until it works itself loose

Had a friend bring one to me the other day.  Shimano Octalink BB and chainset with a seized bolt.  Bolt head had been wrecked in their attempts to remove.

It started with me just offering guidance.  Ended up with me joining in.  Tried everything to get the bugger off.  Sawing the axle, cutting two slots and prising and tapping off.  In the end after a couple of fruitless hours I gave up and broke out the angle grinder.

10 minutes of careful work later the crank and spider were in 5 pieces lying on the floor.  Luckily he was removing the crank to change the groupset including BB – so it didn’t matter that I had to destroy the thing.

If it’s left side stuck try removing from the right side of the frame, can get a lot of leverage there with a massive spanner on it. The crank presses against the frame and is forced off the axle asthe BB comes out the other side. Not great for the paintwork but done it once and it worked. Wouldn’t work the other side as you’d just take the wee plastic cup out and that wouldn’t do anything.