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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!

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

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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!

Criggie
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sabgenton
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  • What sort of fire was it exposed to? – Carey Gregory Apr 11 '14 at 06:10
  • I 'think' it was in a house fire. – sabgenton Apr 11 '14 at 06:16
  • I'm only assuming its alloy but yeah very light for steal heh. – sabgenton Apr 11 '14 at 06:26
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    Well, the fire was barely enough to even scorch the paint, so unless that's a carbon frame I wouldn't worry about it at all. – Carey Gregory Apr 11 '14 at 06:30
  • Yeah, if the heat wasn't high enough to make the paint peel off then I doubt that the frame's integrity is affected. (It was an odd fire, though, to scorch the top tube like that and not cause any apparent damage to the seat, plastic bottle holder, rubber tires, etc.) – Daniel R Hicks Apr 11 '14 at 11:33
  • I would suggest checking the headset bearings, as heat could have affected the lube there. And if that seat stem is carbon it could be suspect. – Daniel R Hicks Apr 11 '14 at 11:35
  • first thing I would do is check that fork crown. Heat could have transferred down the steerer tube and affected the carbon fork. – Will Apr 11 '14 at 16:42
  • Its a aluminium frame (note the "Alpha" logo). I don't think the fork is carbon fiber, but you should be able to check bikepedia or something to match what kind of frame it is. You can always also get another frame and transfer the good components to it, if it makes you feel safer (which is an important consideration). – Batman Apr 11 '14 at 17:20
  • @DanielRHicks No the seat was melted down to the metal that clips in to the seat pole.. The seat you see in the photo is brand new, maybe I should have left the melted seat goo on heh. – sabgenton Apr 12 '14 at 02:45
  • The fire melted the tape and shifters into the handlebars. The hard plastic of the shifters survived but the leavers curled up being carbon. When I took the drop bars off they stuck a bit to the stem so the metal was trying to fuse, left an imprint on the middle of the bar. – sabgenton Apr 12 '14 at 02:51
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    Weird fire. Didn't touch the tires?? – Daniel R Hicks Apr 12 '14 at 02:51
  • The headset bearings are almost certainly cooked and need to be removed and cleaned/relubed or replaced. – Daniel R Hicks Apr 12 '14 at 02:53
  • 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! – sabgenton Apr 12 '14 at 02:54
  • If there is going to be a problem with the frame it would most likely develop where the top tube joins the seat tube or the head tube. If you regularly inspect these areas for cracks for the first several hundred miles (avoid applying heavy paint to the areas) then you should be OK. (I think the folks on that other forum were overreacting a bit.) – Daniel R Hicks Apr 12 '14 at 03:01
  • I guess the downtube would not break at the same time as the top tube without one of the tubes showing some cracks? I might replace the Bontrager steam it has rough metal where it connects to the dropbars. – sabgenton Apr 12 '14 at 03:07
  • Wouldn't want to go chest thru the stem while biking! – sabgenton Apr 12 '14 at 03:14
  • The one thing left on the bike is the carbon-fiber seat post should I replace it? – sabgenton Apr 12 '14 at 03:27
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    The great thing about this bike is it looks less shiny so I hope the thief picks it last hehe :D – sabgenton Apr 12 '14 at 03:28
  • @sabgenton absolutely replace anything carbon fibre that's been in a fire. I would wager that the fork legs are CF as well. – Phil Willoughby Jun 22 '14 at 18:36
  • Its now two years later - what did you end up doing? If you rode on this frame, did it survive or fail? Please post an answer with whatever you did and found out, and then accept that answer as correct. – Criggie Mar 28 '16 at 05:59
  • I see this question is now 4 years old, and you haven't posted anything since asking this one. Hopefully your bike decisions have not incapacitated you :-/ – Criggie Apr 18 '18 at 13:24

3 Answers3

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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.

Marc7654
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As Marc said, with the heating of the frame, it's impossible to know how strong it is but I wouldn't ride it. Given you can pick up a carbon frame and fork from a reputable Chinese manufacturer for a few hundred dollars, the risks are not worth the rewards. Get the parts, dump the frame and then buy something else (a second hand Madone frame can't be that expensive on ebay).

atlaz
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I would chuck the whole bike - its nothing more than scrap metal now.

Its just not worth the risk.

Criggie
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