Help: Really, Really Stuck Crank Bolt

[sq_root_of_2]

Got photos?

 

[breezerboy]

Drill a 5/8" hole in a piece of 1/4" plate 12" or so long, peel out the rubber/plastic seal around the offending bolt.

Line up the hole with the rounded out Allen head, weld through the hole into the bolt up into the flat bar,

Let cool!

Undo,

or you could even try welding said rounded Allen Key onto it, bear in mind this takes more skill to NOT melt the crank.

I'm not sure how cutting the Axle is going to help? you will still have the stuck piece in the crank, yes you'll be able to get the BB out of the frame.

Agree that this is the best method. Try some welders heat sink putty on the crank arm to try and limit any heat damage (melting) of the alloy.

http://www.muggyweld.com/coolblue.html

 

[dyna-ti]

weld through the hole into the bolt up into the flat bar

Just as well everybody keeps a spare mig welder in the kitchen cupboard

 

[xioly]

Chuffing heck, I just been drilling for 20 minutes and am getting nowhere. Another load of knackered drillbits though. Sod the cranks, I just want the BB out now..

 

[dyna-ti]

If you have a sharpening stone of any sort,you can put a very basic edge back on the bit.
It wont be great but it will suffice :?

 

[xioly]

I'm going to try more drilling tonight I can't even get a hacksaw blade onto the axle. I could get bored with this fairly quickly.

 

[xioly]

Sorted

use a seatpost over an allen key to give you the extra leverage!

easy.

 

[Tallpaul]

Well, it's out

Punched out the snapped tap from behind by going through the axle, then drilled it out further and wound in an even bigger LH tap. Took some effort though.

 

[coomber]

And have you got a great big sense of achievement for perservering?

 

[Mattythemod]

Well i have just tried to remove my driveside chainset wich was fitted with one these self extracting crank bolts and yes you guessed it its stripped and i have started to round the allen head off by using too much leverage !!

Gonna soak it in oil now for a bit and put the kettle on and then have another go .