Alu frame fatigue?

[ermsamermsam]

Hi
I bought a '91 aluminum trek frame off ebay for 10.99 on a whim and whilst pondering my next step I have noticed a couple of non random cracks or corrosion bits on the paintwork.. The main one is on top of the seat tube at the back, just below the joint. It is very straight and horizontal in the middle of the attached picture. Is this the frame fatiguing/cracking (I remember hearing that alu frames would just give up at some point)? Or is it likely to be something else, eg paint corrosion? I guess it might be a bit hard to tell based on the photo, but all clues welcome....

 

[cannondale king]

that my boy is a prime example of fatigue in your frame think of it as an alu spoon you bend it and bend till it gets harder and harder then snap its called work hardening it happerns a lot in alloyed metals (differant metals have differant work hardening lifes) my advice garage queen only buddy sorry to say :shock: :shock: :cry:

 

[Err]

Looks bad to me.

 

[shovelon]

Yep, looks like a typical crack.

Oh nay you say, "never weld on a weldment". Pish-Posh. Forego the preheat, cold weld with high strength filler, allow the heat affected zone to age naturally for a week instead of heat treat, and have at it.

If you want to spent the money, weld repair it. If you want to trash it, I will take it off your hands for you if you are in the States.

Beware, if you have it welded, go to the easton products web site, and download the PDF on weld fabrication techniques. Read it and then see someone who gets it.

 

[novekili]

Dunno, that Trek isn't welded. Some kind of "Internal lugs" were used. Alu tubes were glued onto these lugs. The horizontal crack follows the tube-lug bonding line, so it seems as if the tube is detaching from the lug itself.

 

[ermsamermsam]

So, your saying I have to tell my wife that the frame I bought, that led to me buying all those cranks, wheels, seatposts, skewers all that shit' is kacked and I also need to buy another frame? Anybody got any tips on how to do that and make it out the other end?
Given that the frame only cost 10.99, I doubt I willl be coughing up for any repairs......... Hmmmm

 

[scant]

I'd be contacting the ebay seller & asking for your money back.

 

[utahdog2003]

Dunno, that Trek isn't welded. Some kind of "Internal lugs" were used. Alu tubes were glued onto these lugs. The horizontal crack follows the tube-lug bonding line, so it seems as if the tube is detaching from the lug itself.

Ditto that.. The Trek in those pics is bonded aluminum. The lugs are separating. It is now junk. :cry:

 

[South Bound]

You are now doomed. Only way out is to go and buy something that looks the same and hope she does not notice!

 

[monsterfatuk]

get your money back from the seller,and start again