Bicycle Mechanics - Stripped 8mm self extracting crank bolt

Picked up an older bike today with XTR octalink crank/BB and the drive side 8mm self extracting crank bolt is rounded out. Sure some of you guys working in shops have run into this before. Anyone have a good coarse of action for getting it out? Thanks

The 8mm bolt is rounded out? That's scary.

If it was my bike the first thing that I would do would be to use a pin wrench to remove the self-extracting collar. Then I'd see if a brand new 8mm allen wrench will remove the bolt. If that doesn't work, (and I doubt it will), I'd go to a tool store and buy an EZ-out and the proper size drill bit to go with it.

Good luck.

Dremel tool and prayer?

Octalink bottom brackets have a hollow spindle with a 15mm ID and the fixing bolt has (or in your case, had) an 8mm hex so drilling the hex out with any bit equal to or smaller than 8mm shouldn't hurt the spindle if you keep the drill straight. Once you've drilled through the bolt, an Easy-Out should be able to grip the bolt and remove it.

Thanks guys....that's pretty much what I'd thought. Will put the frame on a drill press and give it a whirl. New 8mm couldn't turn it either. It's just to rounded out in there. I tried filling in around it with thin metal but still couldn't get any bite.

New 8mm couldn't turn it either. It's just to rounded out in there. I tried filling in around it with thin metal but still couldn't get any bite.

Instead of buying a new 8mm, try just grinding the worn ends until you get down to fresh crisp corners.
It extends the life of the allen wrenches.

You can also try to find a torx key that is just a bit too big to fit in the 8mm bolt head and pound it in. Have done this on many bolts before and works fairly well most of the time

^that was gonna be my suggestion. torx it.

Take a dremel and cut in a slot so you can get a flat head screw driver in it and get the biggest flat head you an find. It'll be tough to try to get it out with a flat head, but its worth a shot before you completely drill through the head

what the hell is an "easy out"?

what the hell is an "easy out"?

Something you use to extract broken screws and bolts.

http://www.madelectrical.com/workshop/broken10.jpg

what the hell is an "easy out"?

Tool stores or better hardware stores will have them. It kind of looks like a tapered drill bit with a left hand thread. First you drill a hole in the fastener that you're trying to remove with a regular drill bit that matches your EZ-out. Then you screw the EZ-out counter-clockwise into the stuck fastener. As it bites in it will back the fastener out.

You can also try a slightly larger american sized allen key.....pound it in tight with a hammer.

the easiest way I can think is use a punch and a hammer to get the bolt moving then use the torx trick to spin it out the rest of the way

Just a couple days ago I had an allen bolt that the head rounded out on from rust (bought a used bike that'd been stored in a shed) and I just ******d it really good with WD-40 and hammered a regular slotted screwdriver into it (gotta love dollar stores for disposable tools), then gave it a twist with a pair of channel locks on the handle, popped it right out.

EZ-outs are what keep the EDM people in business....