Ya' know, the ones that cut anti-clockwise. VERY handy for stuck bolts. Have you tried tightening the bolt? If you can get it to move, even 1/64th of a turn tighter, it will probably come out with a reverse bit and/or an easy out.

I like the 2 lb sledge hammer idea, too. Impact is a wonderful thing!

Jay.

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On the road, currently:
'83 300D (German spec.) 168k mi. - - Wolfgang (tucked snugly away for the winter!)
'87 300D 375k mi. - finally went over to "The Dark Side"
'87 300TD 225k mi.
Cannondale 66cm CAAD5 w/Campy/Jamis Aurora
Hujsak Custom Fixie/Landshark Track Shark Custom/Ahearne Custom 29'er