Stuck Crank

[HillAversion]

I'm trying to remove the cranks from a Specialized Expedition bike to install a Bafang motor, but they're not budging. I've got the hex nuts removed, but it looks like the space inside is a square that's smaller than the round end of the Park Tool crank puller I'm using.

Before I start going ape on this thing with a mallet, does anybody have any wisdom to share? I don't want to damage anything.

 

[red]

Hill,

You may need a tool that fits inside the crank correctly. You may be able to place a small nut on the square shaft, and press on the nut, using your tool. If you have a heat gun, that may help, but shield the bike from the hot air with some metal plates - a heat gun gets hot enough to melt tin/lead solder. Don't get the crank any hotter than necessary. When the crank is under pressure with the tool, and hot from the heat gun, a sharp rap on the outside of the crank with a hammer may do the deed. Do not pound on the crank. Make the strike at the corner of the square shaft inside., and maybe two corners. Once the crank pops loose, relax. The rest will be easy.

 

[HillAversion]

Thanks, Red. I'll give that a shot.

 

[red]

Thanks, Red. I'll give that a shot.

Hill,

You can also try rust penetrant or kerosene (such as WD-40) first, but leave it on the job overnight, before you start in with the tools.

 

[sojourner]

That Park tool looks wrong; The bolt that you removed; will it thead in far enough (without the washer) to use as a fulcrum?
I remember, when cotterless cranks first became common, 50 years ago, inadvertently leaving the washer, (they were not captive then) in place. Not Good

 

[HillAversion]

Actually, the Park Tool crank puller worked. I just needed to really torque down hard on it. Didn't break anything and the crank gave way.

One small victory. I hope to finish this project in the next couple days.

 

[Vaf513]

I had to use an impact gun on mine. Cordless. Came right off