So I went to take my cranks off tonight. I bought a frame and my lbs fitted stuff to it 12 months ago.

Undid one bolt, fine, turned 180 to get to the other one and it’s rounded. As in properly rounded. Bloody annoying to be honest, they’ve been as ham fisted as anything and must have realised they were stripping it*

What are my options now? I’ve tried chucking a torx in there as read before that can sometimes work but that didn’t help. Get the drill out? I’d prefer to save the crank but if it has to go it has to go.

*genuinely the lbs and not me. This is my first attempt at building up a bike hence my increased posting of stupid questions.

Tighten the first one again to relieve some of the tension from the stuck one, and remove with new Allen key/hammered in torx key/EZ-out.

You can just drill them out. If you’re reasonably careful you won’t damage the cranks. Start small and go up in drill sizes. I’ve had to do this a few times, the cranks and chainrings have always been fine afterwards.

Thanks guys. It’s non drive side so I have a bit of space to work. Just really annoyed they’ve been so clumsy and it’s a job I didn’t think I’d have to worry about

Try the tighten of the other and a new torx bit as mentioned . It really will take the tension

Ignore what I said about drilling it out, I was thinking of chainring bolts.

Tighten other side, cut slot in head of rounded bolt with a dremel and unscrew by tapping round with flat blade screwdriver and hammer.

Have done this to get security screws out so should work on crank bolts assuming you have clearance to cut the slot.

If I need to resort to it, do those EZ out / screw extractors work (well)?

I was searching for tips on removing a stripped bolt (I’ve got one to get out of my car). Someone suggested using valve grinding paste to give yourself a bit more grip. I imagine something like carbon assembly paste might also work.

I’ve not yet tried it though.

Thanks for the replies. An update if anyone cares:

Torx didn’t work, just span as it was so rounded already.

No chance to dremel as it is recessed.

Took it to my old man who is quite handy and he welded a new bolt to the knackered one and then unwound that…worked a treat.

Now I need to get time to build the new bike!

Thanks for the help
Stu

Nice one mate, glad you got it sorted!

I’ve drilled out bolts from the opposite side of stems. Also used the EZ out. Glad it came out OK for you.