Results 1 to 10 of 10
  1. #1
    mtbr member
    Reputation:
    Join Date
    Mar 2010
    Posts
    2

    Replace head tube?

    I'm not much of a bike mechanic but i am an auto mechanic and a welder with access to just about any welding tools i could want and limited access to a machine shop. I had a giant iguana for the past 6 or 7 years. Just got into biking a lot in 07. I moved to Detroit and started using my bike to commute to class. Needless to say my bike was stolen. Lock cut and bike gone from out front of class.

    A neighbor gave me an older schwinn frame for free and sold me a junk frame with a bunch of nice parts on it for $50. I planned on putting the good parts on the good frame. The good parts included:
    Rock Shox Judy XC front fork
    T gear crank
    shimano shift and brake pods
    nylon cables
    shimano draillers
    2 straight aluminum wheels
    front brake assembly

    Well i tore down both bikes (except for removing the crank because i dont have a crank removal tool at the moment. Turns out the Rock Shox front fork has a 1 1/4" tube and the head tube on the schwinn frame is 1". I like the schwinn frame, its a good size and its simple. So i want to keep the frame. I also dont want to have to buy a new fork.

    Has anyone welded a new head tube to a frame before? If so how did you go about doing it? what are somethings i need to watch for or any pointers you may have?

    Is this a completly stupid project? looking for some insight.

    How did you make a new head tube? machined? welded multiple pieces of tube? do people make head tubes?

  2. #2
    Who turned out the lights
    Reputation: Francis Buxton's Avatar
    Join Date
    Apr 2004
    Posts
    1,114
    I hate to tell you, but it will be way more work/risk/hassle than it's worth. When you cut the old head tube off, you will end up shortening both the top and down tubes. It will be pretty hard to keep your head tube angle/alignment correct without a jig of some sorts.

    You also haven't mentioned if they are both steel or not.

    You can buy head tube stock, but again, I don't think it's worth it, even for a learning project. You'd be better off cutting off the front triangle, at which point you might as well try to build an entire frame from scratch.

    I'd sell one or both frames and try to come up with something else that will work.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Feb 2009
    Posts
    434
    PROCEED WITH CAUTION.........think of your teeth. and how long road rash takes to heal when its on your face...........
    Since the new head tube will be larger, you will have a little bit of room to remiter the ends of the tubes. use a hand file not a power tool for remitering the tubes, you want full contact all around both pieces of tubing to your new head tube. If you say you are a welder then I believe you, make some practice welds and destroy them with cheater bars and a big vise. if you break a weld instead of completly mangling the tubes give up on the project and walk away. Make sure every thing is clean-clean before you start , inside and out of all three tubes, when you finish cleaning with the sand paper, use alcohol to wipe the joints down before you weld. Spend some time thinking about your plan to align the new head tube with the centerline of the donor bike. You may need to think about doing some extensive measuring before you cut.
    Have fun.

  4. #4
    Anti-Outsourcer
    Reputation:
    Join Date
    Jan 2007
    Posts
    319
    We're also talking like .035 wall tubes here. So best case scenario, it's like trying to do a fillet on 20ga sheet rolled into a 1" diameter. Don't know what kind of welding you typically do, but this might not be your norm.
    +1 on the teeth thing.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Mar 2010
    Posts
    2
    thanks for the input guys. I do think if I took my time and measured everything and made sure the fit was good I could weld it in successfully but I have decided to head your warnings. I found a guy at a local shop that's gonna trade me a frame what will fit my parts for the frame I've got. That's way I don't have to buy the new head tube either. Thanks again for the help

  6. #6
    mtbr member
    Reputation:
    Join Date
    Mar 2007
    Posts
    134
    Very cool. I have not had a chance to build a frame yet but did just this exact same thing recently to an old Giant. The GF liked the bike but it had a 1" head tube. I bought a 1 1/8" tube from Nova, trimmed it on my lathe to size nice and square. Mounted the frame on a jig on my mill and used a custom cutter to establish a perfect miter. I also changed the rake a tad to better suit the new fork geometry. Then tacked it all up. I used a heat sink in the head tube and back purged it as well. TIG welded and then used a head set reamer and reamed out the bores to exact size for a spare King headset I had laying aroung. It looks beter than new. Fun project but quite simple really. My only suggestion would be that if you are not comfortable welding thin tubes then practice, practice, practice first. A good miter on the joints and proper alignment is also important. If you are comfortable with fabrication and welding thin material then I say go for it. Good luck. Go green, recycle, re-headtube and reuse.

  7. #7
    locked - time out
    Reputation:
    Join Date
    Jan 2010
    Posts
    759
    It's very possible. There's actually another thread running right now where someone else changed their headtube. Lots of nay-saying ninnies there, because they caqn't do the same themselves, but lots of tech talk in there is convincing.

    Go for it, and don't let the internet nay-saying ninnies tell you no. They just like to throw money around as a solution to everything.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    7,693
    Quote Originally Posted by glitz
    Go for it, and don't let the internet nay-saying ninnies tell you no. They just like to throw money around as a solution to everything.
    Everyone in this thread gave good advice. It's something where, if you're not comfortable with it, then you probably shouldn't do it given the costs of failure.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Mar 2007
    Posts
    715
    Quote Originally Posted by bvallerand
    I have decided to head your warnings
    OMG! somebody actually listening on the internet....Miracles do happen
    All the best,

    Dave Bohm
    Bohemian Bicycles
    http://www.bohemianbicycles.com
    &
    http://www.framebuildingschool.com

  10. #10
    pvd
    pvd is offline
    mtbr member
    Reputation: pvd's Avatar
    Join Date
    Jan 2006
    Posts
    2,803
    Quote Originally Posted by dbohemian
    OMG! somebody actually listening on the internet....Miracles do happen
    Wow! I'm in shock myself.

Posting Permissions

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