Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Senior Member B1105's Avatar
    Join Date
    Oct 2002
    Posts
    592
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Cracked aluminum frame, able to fix by welding?

    Hi, I have an aluminum Klein Quantum frame and recently, the derraileur hanger cracked. It did not break off, but is cracked on one side. I was wondering if there were any forms of welding the hanger back together would be possible, (its not a replaceable hanger), so, if anyone has some feedback, that would be helpful.
    Thanks
    -Byron Ling

  2. #2
    Banned
    Join Date
    Aug 2001
    Location
    upstate New York
    Posts
    1,688
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yes, there are, but they will be difficult to do in a small repair. Have you talked to a decent frame builder, or perhaps a welder? Have you called Klein?
    Je vais à vélo, donc je suis!

  3. #3
    Senior Member
    Join Date
    Oct 2002
    Location
    Colorado Springs, CO.
    Posts
    83
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    A good welding shop should have a TIG machine, which is probably the method most appropriate for an aluminum bike frame. Also, check with your LBS to see if they can recommend anyone in your area who can perform such a repair.
    A man's actions influence his attitude as much as his attitude influences his actions.

  4. #4
    Apot. sshock4's Avatar
    Join Date
    May 2002
    Location
    new brunswick, nj
    Posts
    191
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    hah....good one byron

    -Andrew
    surly1x1

  5. #5
    Senior Member bentbaggerlen's Avatar
    Join Date
    Sep 2002
    Location
    New England
    Posts
    714
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yes, your hanger can be repaired. I done a few broken hangers on aluminum frames. I think Kline bikes are built with 7000 series alum. 7000 series can be allowed to air cool without any big loss of strength. You will have to remove the paint from the area, any paint sucked into the weld puddle will weaken the weld. I still don't know why any frame builder would build an aluminum frame without a replaceable hanger. Its not a huge job, should only take an hour or so. (hard to say without seeing it) Most weld shops would charge $50 or so, some more some less. You will need to strip down the frame. And after repairing the hanger you may need to realign the hanger.

    There may be another way... Take a look at www.exposales.net they sell an aluminum brazing rod. It melts at 735* and flows into the gain of the base metal (alum melts around 1100*) A propane torch would work well. The rod is called HTS-735. I have not used it myself, but I have seen a few things repaired with it. I would not use this to repair a high stress aera such as a cracked headtube, but it should work on a hanger. the rod has a tensile rating of 45,000 psi and shear of 31,000 psi.

    Good luck!
    Bentbaggerlen
    "When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking." - Arthur Conan Doyle

  6. #6
    Senior Member B1105's Avatar
    Join Date
    Oct 2002
    Posts
    592
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Dear bentbagger,
    thanks for the reply, would any welding shop beable to do this? WHat did you mean by strip down? take off all the parts? thanks for this info

  7. #7
    Dances with Rocks Dirtgrinder's Avatar
    Join Date
    Apr 2001
    Location
    Jefferson City, MO
    Posts
    1,441
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You'll have to take off any parts near the hanger. The brake should be far enough away that the heat won't hurt it. If you have a chainstay protector I'd take it off too.
    I would just call around to some of the welding shops and see if they can weld aluminum.
    If everything seems under control, you're just not going fast enough...

    To become a registered member of BikeForums Click Here

  8. #8
    Apot. sshock4's Avatar
    Join Date
    May 2002
    Location
    new brunswick, nj
    Posts
    191
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    and take off all the paint in the region. so it doesnt burn, or fall into the weld.

    ...
    surly1x1

  9. #9
    Senior Member B1105's Avatar
    Join Date
    Oct 2002
    Posts
    592
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    yea thanks a bunch

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •