Monkey wrenching, or quality allen key?

That flatpack furniture won't make itself, will it?

SPD clip? 😉

I suspect the equation was as follows: brake mount adaptor + cheap allen key + bit-o-stealtube

I thought you were talking about that sprinter lad never getting the beers in.

Did it undo ?

molgrips – fnar fnar

happily the bolt let go before the key did

I think that the brake adaptor is mild steel ? and perhaps you have stainless steel pins?
Not a good idea, go like for like..

Does anyone remember those Hope bottom brackets where the special tool had six pins in it that fit into holes on the face of the shell? The pins were a good 2-2.5mm dia. I had a BB that was so tight I had to use a G clamp to clap the tool in place over the spindle then a massive spanner. All six pins bent right over, three were so bent they broke off on tightening up and I had to replace them.

Tightest thing I ever had to undo on the bike, that was.

Just rounded out a rotor bolt – not happy. Any ideas how to get it out?

knock a t20/25 torx bit into it..

Just rounded out a rotor bolt – not happy. Any ideas how to get it out?

Expensive option, but if you are really stuck (and the screw is), some of these and an impact driver do the trick well!
http://www.tooled-up.com/Product.asp?PID=136827

Just rounded out a rotor bolt – not happy. Any ideas how to get it out?

angle grinder to remove the head of rounded bolt. undo the rest of bolts undo stub of screw with pliers.

"Just rounded out a rotor bolt – not happy. Any ideas how to get it out?"
File two edges carefully making sure are parellel and try to get a (Good quality) adjustable spanner round it? Its worked on other bolts of mine, like bottle cage bolts or Hope Lever Reservoir cap bolts. The extra torque on a rotor bolt could be too much though

hacksaw a groove into it and undo it with a screwdriver

if you can, undo all the other bolts then twist the rotor round and ta daa!bolt becomes loose pliers etc

what mudplugga said, undo all the others first and see if the rotor will rotate on it a few degrees.

You can drill the heads off bolts too, then remove the rotor and drill the rest out carefully.

what fuzzybear said, many rounded out allen heads can be recovered with a torx being "encouraged" to fit with a bit of force.