How bad is this fire damaged alloy frame? I got this Shimano Ultra groupset bike for free, all I need now for it is shifters as the carbon and rubber melted in them and the original seat.

But now I am wondering if I can get away with it, I don't want the top/down tubes to brake off the head!



The cable adjuster on the down tube is a bit melted on this one if you zoom in:




Everything works great (Not to say I know if there's a good amount of lube in the head tube but it turns fine)  but what do you guy think is it too dodgy to keep aluminium that has all that darkening round the welds?

I know a lot will say biff it and I should at least get a new stem but please give me some disclaimer-ed thoughts for a proper like myself just wanting a bike that has better gears than Shimano tourney!

EDIT:

This is what concerned me: http://forums.mtbr.com/tooltime/repairing-fire-damaged-bikes-689507.html They tell the guy to ditch a bike with no viable damage!

It would be interesting for example to know what temperature it takes to melt the old bike seat completely of the metal guides and curl the shifter carbon leavers!
I've done a bit of aluminum anodizing which requires annealing (softening) of the metal. This happens at about 650F. You mentioned the drop bars being melted so I suspect the top tube is likely annealed and won't have the same stiffness as it's suppose to. It may flex more than it should and may cause other parts to flex more also.

The head tube bearings were also mentioned and should be checked. I also wouldn't trust the seat post.