Help, Stripped Head Of Damper Rod Bolt Taking Forks Apart

So I am replacing fork seals and changing out the springs on my 97 VFR, right fork comes apart no problem.  Left fork however, is turning into a nightmare.  I used an impact wrench with a 6mm hex head bit and managed to strip the head out and the bolt wont budge.  I've read that some people need to drill the head off and when you pull the fork apart the the remainder of the bolt should just unscrew from the damper.  

So those who have done this.  What size drill bit? Did you use a hand drill or drill press?  Should I just take it to a machine shop?

Thanks,

Gary

I've had it happen on a bike, not a VFR.

If you have the other bolt, measure the thread diameter and use a drill bit that is slightly larger than that. That way when you drill past the head it will pop off. You need to have the fork

off the bike and in a vice, and either the spring installed or have someone pull on the lower part of the fork leg, or both so the bolt won't spin when you try to drill it. That's how I did it.

You can start with a small drill bit like an 1/8 inch or so for a pilot hole. This makes drilling the larger hole go easier. Use good drill bits that are new. Good luck man. It's not really too hard.

Another way that generally works is if you have a torx bit set then find a size bit that is just bigger than the now rounded bolt head and hit it into the top of the bolt and it will make its own grooves as you hit it home and grip the bolt. The hitting of the torx bit in will also shock the bolt lose most times. Don't rattle gun it though. Put the fork in a vise now and use a spanner or ratchet to turn the torx bit whilst pushing down on the top of the bit.
As a mechanic I come across plenty of rounded Allen key headed bolts and this works just about all the time unless the bolt is rusted in solid.
Good luck

what about welding another bolt onto the stripped one???

I drilled it out, not nearly as bad as I was thinking it might be. Went slow and as soon as I saw a little line of the copper washer I hit it with a punch and the head popped right off. I was able to unscrew the rest I the bolt by hand after I pulled the forks apart. I had already tried the hammer in a torx bit approach. I think that maybe the previous owner over tighened it and the copper washer caused a mechanical lock of sorts.

Yup, you got it. Nothing to stress about. Just try them and if they won't unscrew grab the drill and keep going. No time lost. Vise grips on the remaining body after the fork is apart. Bob is your uncle...

Just went through this with my truck exhaust manifold. Welding a nut to it worked like a charm.

You cannot get to the head to weld it, though.  It is buried within the slider (that's why you need a long Allen to get it out).  Those are special, narrow head cap screws, which means there is less meat for the Allen key to grip to start with, but if you try to loosen it without a proper long 6mm Allen socket, and worse, try doing this bending over upside down with the forks still mounted, it is easy to round them off...

You've got it sorted, but another trick if you have to drill is to use reverse drill bits--that often backs them out all by itself.

Ciao,