Removing a crank with a destroyed thread

[Big John]

I've seen a team of eager eeejuts waste endless hours of their lives beating a bike senseless trying to remove an awkward chainset only for the bike to be rendered utter scrap at the end of it all. Another one for the scrap pile. The trick is to know when you're beaten and move on. Don't bother with an angle grinder. That's what they used and boy could you see it. The ball joint splitter looks promising though but I've tried a bearing puller and got nowhere but that was probably me being ham fisted.

 

[Gunk]

I've seen a team of eager eeejuts waste endless hours of their lives beating a bike senseless trying to remove an awkward chainset only for the bike to be rendered utter scrap at the end of it all. Another one for the scrap pile. The trick is to know when you're beaten and move on. Don't bother with an angle grinder. That's what they used and boy could you see it. The ball joint splitter looks promising though but I've tried a bearing puller and got nowhere but that was probably me being ham fisted.

I agree, had this with stuck seat posts, two days on a frame worth sod all, better to strip it of useful parts and chuck it away.

 

[classic33]

I've seen a team of eager eeejuts waste endless hours of their lives beating a bike senseless trying to remove an awkward chainset only for the bike to be rendered utter scrap at the end of it all. Another one for the scrap pile. The trick is to know when you're beaten and move on. Don't bother with an angle grinder. That's what they used and boy could you see it. The ball joint splitter looks promising though but I've tried a bearing puller and got nowhere but that was probably me being ham fisted.

I've used the pedal with a loose bolt method to free the chainset, a gear puller and as a final resort an angle grinder.
Success with all three methods, with the "trick" being knowing when it isn't going to work, stop and try another method. Only used an angle grinder a couple of times, but as with using any power tool, keeping an eye on what you're doing is important. Metal warms up during cutting, so might just free it enough to finish removal by one of the other methods.

 

[Andy in Germany]

I agree, had this with stuck seat posts, two days on a frame worth sod all, better to strip it of useful parts and chuck it away.

I think that may end up being the end result, as the seatpost is pretty stuck.

It's a shame because it's the perfect frame: lugged chromoly and designed as a touring bike with vertical dropouts: a very rare combination. I'm spraying the seatpost with rust remover, and I'll try clamping it and turning the frame later, but I'm not hopeful.

 

[mickle]

Dremel a slot to within a few mm of the bb axle. Insert flat head screwdriver and tap it in to propagate your slot into a crack. The crank will drop off.

 

[classic33]

I think that may end up ebing the end result, as the seatpost is pretty stuck.

It's a shame because it's the perfect frame: lugged chromoly and designed as a touring bike with vertical dropouts: a very rare combination. I'm spraying the seatpost with rust remover and I'll try clamping it and turning the frame later, but I'm not hopeful.

Plug any hole in the seatpost, turn the frame upside down and fill the seat tube with cheap cola.

 

[Venod]

I agree, had this with stuck seat posts, two days on a frame worth sod all, better to strip it of useful parts and chuck it away.

I have just saved a nice Planet X carbon frame with a stubborn stuck seatpost, it was 31.6mm, the id was near enough 27.2mm to fit a post of that size, so that's how I am riding it at the moment.

 

[Andy in Germany]

Plug any hole in the seatpost, turn the frame upside down and fill the seat tube with cheap cola.

?!

What does that do?

 

[classic33]

?!

What does that do?

Supposed to be safer use than caustic soda.
https://www.cyclechat.net/threads/seized-seatpost-victory.228392/post-5090175

There's a few methods you could try
https://www.sheldonbrown.com/stuck-seatposts.html

 

[fossyant]

TNT.

 

[fossyant]

Nuke if a bit stubborn

 

[C R]

And if all else fails there's the Fawlty approach

 

[Punkawallah]

The nice chap at BCR on t’YouTube has shown that his most cost effective method for removing a stuck seat post is to ream it out with a power-tool. And the options included an expensive, 6’ high mechanical remover imported from France :-)

 

[Cycling Badger]

Can testify that caustic soda will dissolve an aluminium seatpost stuck in a chromoly frame.
Would not recommend as first option; but if all else fails and it’s that or bin frame I’d do it again.
We used high concentration made from crystals and repeated applications.
Frame needed some painting afterwords, despite efforts to minimise damage to paint - maybe we could have tried harder on that point.
[Before resulting to caustic soda we had tried cutting out the seatpost with vertical cuts using a hacksaw blade - this didn’t prove successful.]

If the alloy crank has bonded to steel spindle with galvanic corrosion and mechanical or less corrosive chemicals (ammonia) won’t brake bond then caustic soda may - but at the expense of the cranks. However, I think I’d rather try cutting off the crank before resorting to dissolving it.

 

[Gillstay]

To remove a chain wheel I use a hacksaw /Dremel to cut to the steel spindle then a small sharp chisel to open it up the rest of the way.

Seat post, either good penetrating oil and heat, then vice, or caustic soda and then paint. Good luck.