In summary, tried to remove the rear mech hanger on my carbon frame. Two bolts so tight, got one out the other will not budge. Snaped an Allen key and now completely rounded the bolt hole. It is completely flush with the carbon frame so cannot get any grip. I can only think of taking things slow and drilling but thought it best to consult the masses before I do something else stupid.
I do have a great LBS and happy to pay for it doing, but if it’s a case of drilling or some other blunt method, I’d possibly prefer to take a little more time / care and do it myself.
All good ideas great fully received. I’m big enough to take the on slaughter of stupid boy comments. Thanks
Ps have applied lots of WD.
Also mech bolt to hanger is ridiculously tight.

http://www.screwfix.com/p/trend-pro-grabit-screw-and-bolt-remover-2-pieces/21391

Would this work?

They’re normally threadlocked in place. Soak in boiling water to soften the threadlock and see if you can find a forx bit that is a tight fit in the new internal dimensions of the bolt head.

Using some kind of penetrating oil over a few days I’ve heard can loosen things. I took my bike with its crank bolt stuck fast to my lbs and they tried widening it to get the next size Allen key in…and then had to drill it. Worked out well, as they got a decent size drill bit to grip the inner of the bolt…shoved the drill into reverse and hey presto bolt unwinded itself and no damage to the threads. Cost me a tenner and a pack of beer. Take it to the lbs IMO if you’re not mechanically minded like me!

Or an imperial hex key that’s slightly bigger than the metric one.

Thanks for the ideas all. I’ll keep up thw WD treatment and think a bit more. I’ve tried getting a torx into but no joy, also tried an imperial hex. Think will give both another go. If no joy, will check out that removal tool thing or LBS.
Thanks for input guys, any more ideas great fully received.

Put the other bolt back in, it will relieve the pressure/friction on the head of the stuck bolt.

Penetrating oil for a start… Not wd40. Not sure about hammer use but..
Hammer a cheapo slightly bigger hex socket driven key in it and use an impact driver?
Cut a slot in it with a dremel diamond disc and use a slotted bit and impact driver.

New bike time.

As above, use penetrating oil.

Hammering a torx bit in to your mangled hex head might also work, and as suggested above, try putting it in boiling water.

Just drill it. It’ll take 2 mins and then that’s it done. Try and clamp/secure the frame but also have a mate there holding the rear stays.

Get yourself an easy out set from your local tools shop like this one here

They have got me out of a jam on more than one occasion

Another vote for and Easy Out – the bolt that holds my brake pads in suffered a similar fate. 10 minutes with an Easy Out and it was free. On;y damage was to the bolt.

Just don’t snap the easy-out inside the bolt. Easy to do if the bolts as tight as you say

For most folks, the first easy-out experience is of snapping off the easy-out and now having to deal with a stuck bolt with an indestructible bit of hardened steel stuck in it. Especially with smaller easy-outs.

Any chance of a pic? The thread will be in the mech hanger, unless it’s a really weird frame, so just drilling the head off will remove the hanger. Then you can probably get the stub out and reuse the hanger. It might also be possible to do it from the other side. (ie drill out the stud til the cap falls off), that’s a bit of a long road for a shortcut but is less likely to end up with a drillbit stuck in a bit of carbon.

All in all,if you’re not comfortable with it and it’s a one-shot deal, there’s a lot to be said for getting a pro to do it.

Exactly the same happened to me with my carbon frame. Had a moment then calmed down. A drill was far more controlled than any hammering and easy outs would be. Take your time and get the frame nice and steady.

Thanks for everybody’s input. Decided to do nothing today but give it more thought. I was not aware of the extractor tool but reading the reviews and comments I’m 50/50 on buying one.
I will buy penetrating oil as opposed to wd40. Sorry I can put pic on, I’m a complete numpty when it comes to posting pics computer tetchy. It’s is a small countersunk bolt, countersunk head on inside of frame, ie where wheel goes. On outside I can just see the level end of the bolt stuck in the hanger. The hanger is shot, hence why I want to replace it.
I sit here with a beer, reading all the input and trying to decide which way to go. I think drilling may be best…. Or possibly going steady with the extractor tool. I really don’t understand why it’s so bloody tight.
Will post up, when it’s out. Hopefully soon. Cheers.

It’s tight due to the threadlock. Some of them can be resistant to chemicals so may not soften with penetrating oil. Try heating gently to break the seal on the threadlock.

Take a sacrificial Allen key and araldite it into the bolt ….. Simples