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  1. #1
    Junior Member kf6pfk's Avatar
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    Repairing a weld in a aluminum swing arm assembly

    Hi all,
    I am the owner of a Trek Y22 mountain bike. I have found a small crack that runs along one of the welds in the rear swing arm assembly near the pivot point. I like the bike, but have been told that the swing arm is no longer available. Could it be a reasonable repair for someone familiar with welding aluminum? I was going to try to find someone at one of our local small aircraft repair shops who might like to take it on. I fear that the heat generated when TIG welding the bad seam will knock everything out of alignment. If that happens, I have no way of getting things back to normal, so I don't know if it's even worth bothering with. Any ideas?

  2. #2
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    hard to say without seeing the creack. If you could find out the exact alloy, 7005 or 6061 or whatever that would be a big help for the welder. A good repair would be to fix the crack with a weld and to weld on a extra gusset on both sides of the swingarm to reduce the load....but a poorly shaped gusset could make it weaker..

  3. #3
    Junior Member kf6pfk's Avatar
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    I can't really tell by looking; so I've emailed Trek tech support for the answer.

  4. #4
    Junior Member kf6pfk's Avatar
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    From Trek TS " That is 6061 and then is annealed and aligned then aged to T6." , So it Sounds petty hard to fix to me.

  5. #5
    Senior Member ftwelder's Avatar
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    Do you have any photographs?
    1886 Surrey machinists Invincible, 1900 Nashua, 1937 Raleigh Golden Arrow, 1938 Raleigh Silver Record, 1951 Armstrong tourmalet, 1970 Motobecane Grand Record, 1971 Raleigh Professional, 1971 Gitane TDF, 1972 Legnano Gran Primio, 1973, Peugeot PX-10, 1975 Roberts, 1984 Battaglin Giro, 1985 Grandis Speciale, 2012 FTW

    frankthewelder@comcast.net

    le prix s'oublie,la qualité reste ,(michel audiard)

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