Crank removal (thread for extractor stripped)

[Banjo]

I am helping someone renovate an old Scott Mountain bike with a 3 piece crank set. On the non drive side I cant get the pedal crank off as the internal thread for the extractor to wind into is stripped out full depth.

Tryed an ordinary puller but it kept slipping off the crank. Dont want to cut the crank if I can avoid it. The spindle is really hard metal, tried hacksawing it but 18 tooth blade is just making it shiny.Mayber better hacksaw blade will cut it?

Any suggestions?

 

[Rickshaw Phil]

I had this with a cheap square taper crank set. The threads were flimsy and came out in a coil the first time I attempted to service the cup and cone bottom bracket.

I tried various things but the attempt that worked was pouring liberal amounts of boiling water over the crank and then levering it off.

 

[lpretro1]

Remove crank bolt and ride it round til it drops off.

 

[Alex11]

If you are going to try and cut it off, get an angle grinder, or a drill attachment.

 

[Cooper645]

Start at 2min

 

[Smurfy]

I had this with a cheap square taper crank set. The threads were flimsy and came out in a coil the first time I attempted to service the cup and cone bottom bracket.

I tried various things but the attempt that worked was pouring liberal amounts of boiling water over the crank and then levering it off.

+1

An aluminium crank has a larger thermal expansion coefficient than a steel BB spindle, so heating the crank should loosen the fit.

 

[Cycleops]

Down here they just whack the crank from the BB side with a hammer, works every time. You could try using a piece of wood to avaoid damaging the crank too much.

 

[Banjo]

Thanks for all replies/suggestions. My mate is on holiday so project is on hold for now .Boiling water and a bit of violence sounds promising.Fingers crossed

 

[Ed no-more-lemons]

I am not ashamed to admit that I have stripped a few threads in my time. Mostly as a teenager in a hurry. In steps an adult with a blow torch and all the hammers and stuff, job done with no damage to the paintwork of the frame.

But I am sure I have seen a triple pronged tool online, that closes behind the crank and relies on leverage, it might even have been a http://sheldonbrown.com/ page

Or Ebay which turns up some real gems, as I don't think this sort of thing would be made anymore.

 

[GrumpyGregry]

a three legged crank puller of the right size will do it. Halfords or Fleabay.

With the bolt off, just ride the thing hard uphill. It'll wreck the arm but it will come off.