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  1. #1
    Junior Member
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    tall bike won't handle properly

    Hey all!
    I've been working on this tall bike for the last few days and I don't seem to have the handling down right. When it's clamped under this set up turning the bars on the top bike will force its bottom bracket off the post. I'm sure if I welded it like this then it would either be really hard to turn to the point of probably breaking my welds. What am I doing wrong / how can I get it to work?? Any help is greatly appreciated, this is my first tall and not sure exactly how the pivot points work.

    IMG_20120303_180058.jpg

  2. #2
    Randomhead
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    you need to make the steerers line up, or else use a chain to link the two.

  3. #3
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    Quote Originally Posted by unterhausen View Post
    you need to make the steerers line up, or else use a chain to link the two.
    So you're saying I need to make the headtubes the same angle AND lined up directly, I'll try that now. I'm not sure what you mean by using a chain.

  4. #4
    Randomhead
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    Yes, same angle and lined up. All the pictures I have seen of tall bikes ditch the top fork and extend the lower steerer up to the top steerer.

  5. #5
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    Any ideas on how I would do that with a bottom bike that has a threadless headset? Right now I was going to weld the fork dropouts to the sides of the stem, which is luckily steel, but that makes it not perfectly direct anymore.

  6. #6
    Randomhead
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    weld a tube to the part of the stem that clamps to the steerer of the lower bike.

  7. #7
    Senior Member
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    I agree,flip the fork around in the correct possion and put a short section of handelbar in the lower sten and well bolts out the ends to attach the top fork.

  8. #8
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    Or a drive shaft with a U joint on each end will take up a bit of misalingment

  9. #9
    DelawareDave Dave Armstrong's Avatar
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    christmas07 bikes 006.jpg


    It might be the curved part of the forks on the top frame are throwing off the alignment.

  10. #10
    Randomhead
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    you could look at it that way, the trick is to put the fork dropouts at the same distance from the center of both steerers. It seems that most people just cut the fork up and replace the blades with a piece of tubing/pipe so it's easy to tell if it's lined up and at the right angle

  11. #11
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    i made a jig for mine, a piece of steel pip perpendicular to the floor, strip both frames and slide them on the pipe by the head tube. Then you can clamp them in position with the BB of the top frame seated against the seatpost of the bottom frame. Once the head tubes are aligned then weld the two together at the BB union. Then you can weld in your steer tube, you have to make sure its strong and aligned properly because the steer tube is now supporting the entire weight of the front end.
    03 GT Avalanche 3.0-owned since new, some mods, some road rash. In the midst of upgrades

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    02 Walmart Next drug dealer full suspension chopped and raked. 12 feet total black iron pipe forks, weighs just under 90 lb.

    several projects in various states of construction-decontruction

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