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Help me fix my bicycle

  1. Apr 11, 2007 #1
    i got a new frame for my bike an attempted to swap all the parts (pretty brave i know). when i went to put the parts back the way they were not all fitted. i removed the forks and the handle bars, and now when coming to put them back, the long pin with the hex allen key part will not tighten up. it feels like it has shrunk as it will not reach the whole way down.

    please help
  2. jcsd
  3. Apr 11, 2007 #2


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    Well it may sound obvious but was the frame the correct size? Other than that you can't expect all the parts from one frame to fit a different frame. You may have to buy some new parts.
  4. Apr 11, 2007 #3
    The part that the long hex allen bolt screws into must have fallen inside the fork, you loosened it up too much. Pull the handlebar neck back out and turn the fork upside down to get the part (nut) out. Begin screwing it back onto the hex bolt but let it still be loose when you insert the neck back into the fork.
  5. Apr 11, 2007 #4
    thanks i'll give it a try, The bike is the correct size, as it was previously on that frame.
  6. Apr 11, 2007 #5
    i tried, the part the hex bolt fits in is still too low down, ~an inch or two. what exactly does the bolt fit in, another bolt or directly onto the forks.
  7. Apr 11, 2007 #6


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    Do you have a digital camera that you can snap some photos of the problem? That might make it easier for folks to diagnose and offer suggestions.
  8. Apr 11, 2007 #7
    no not at the mo
  9. Apr 11, 2007 #8
    I believe there should be a circular block thingy with a thread in the centre ,and as the hex bolt is tightened it gets drawn up into the vertical part of the handle bars ,but as the handle bar bit has slits cut into it ,it gets forced apart as the block is drawn in.

    If you cant retrieve it as its come off the bolt buy another one or use a torch and coat hanging and fish it out.
  10. Apr 11, 2007 #9
    Take it to a bike shop, because you dont know what your doing.

    You need special tools to take it apart and put it back together.
  11. Apr 11, 2007 #10
    I used to ride bmx and became very good at fixing bikes.

    To me it sounds like your headtube length is too long and the steerer tube for your forks may be too short. How well does your headset that you were using before fit into your new frame?

    The bolt that holds your handle bars/stem should screw into the steerer tube of your forks.

    It is really hard to say what is going on, I would need to see the forks. Usually the forks themselves are threaded for the stem screw, so I don't know what is going on without some pics.

    is the steerer tube of your forks itself threaded for a screw?

    if you have one of those forks that aren't threaded themself for the stem screw, i would suggest you invest in a pair of forks that are threaded. they are usually much stronger, less prone to breakage, and need less maintenence. it all depends on what kind of bike your have too though.
    Last edited: Apr 11, 2007
  12. Apr 11, 2007 #11
    Using a camera to remind you where everything goes is also great idea with any mechanism. When I was writing tech manuals having a digital camera would have been a dream.
  13. Apr 12, 2007 #12
    it seems like the head tube length is too long but it did originally fit before i removed it. It is a mountain bike.

    i can screw the hex bolt in when the handle bars are not on. but when i put the handle bars back its too short.
    But i know it goes on this bike because it was on it a week ago before i started fixing it (or braking it)
  14. Apr 12, 2007 #13
    Try putting a few washers, and maybe getting a block of wood or something, and use that to pull up the wingnut (the nut that is inside your fork that you want to connect to). Just keep tightening and tightening until it starts to come up. I am not sure if you have a wingnut that is welded to your fork or not, but I know most bmx bikes don't (I'm not sure about mountain bikes though), so this could be possible (I did it with my bike a month ago when I had to replace my headset).
    Last edited: Apr 12, 2007
  15. Apr 12, 2007 #14
    we could always chip in for some plane tickets and send cyrus over there.
  16. Apr 12, 2007 #15


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    When you removed the "long pin", did you completely unscrew the hex bolt? There is supposed to be a nut at the other end...
    What does the bottom of the long pin look like? On my bike it is slanted at about a 45 degree angle. The nut has the same angle. When placed face-to-face the angled faces force the bolt/nut assembly against the body of the fork. If the nut is missing you will have the problem you describe. If the nut is installed upside down (angled face of long pin vs flat face of nut) you will have the problem you describe. If the angled faces of the nut and the long pin are not aligned angled face to angled face, remove and invert the nut. If the nut is located significantly below the angled bottom of the long pin, it will just spin. The fix in that case is to remove the long pin and tighten the nut onto the hex-head bolt finger tight and reinsert it into the fork tube body.
    Last edited: Apr 12, 2007
  17. Apr 12, 2007 #16


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    Wrong size steerer tube for the new frame.
  18. Jun 15, 2009 #17
    I am trying to repair this old bicycle that i just bought. The back gear isn't attached to the bicycle and I have no idea how im supposed to attach it.
    I have attached pictures to help you out.

    Thanx for the help.

    Attached Files:

  19. Jun 16, 2009 #18


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    I just heard this dictionary definition on the new "I'm sorry I Haven't a Clue" on UK Radio 4 …

    Definition of lackadaisical:

    n. a bicyle built for one! :biggrin:
  20. Jun 16, 2009 #19


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    Reassembly is quite easy. However explaining how to do it, so that you understand what we mean, is difficult..

    Since showing, is the best method, my suggestion is to find a friend who knows bicycles and ask her/him how to put it together. You can watch over their shoulder (or bring it down to your local bicycle repair shop).

    If you're still feeling adventurous and want to tackle this yourself, you may want to consult some online video tutorials like http://bicycletutor.com/" [Broken] also provides useful information. Just be careful when screwing it on, not to crossthread the mating threads.
    Last edited by a moderator: May 4, 2017
  21. Jun 17, 2009 #20

    Chi Meson

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    That "C" shaped end of the "gear" (as you called it, the thing is the "rear derailleur") is to be held to the frame by the wheel nut.

    Align the slot of the "derailleur hanger" with the slot of the "rear dropout" (the end part of the bike frame where the wheel is attached). That little plate attached to the derailleur hanger fits into the rounded end of the dropout, and it is supposed to clamp into place there so the derailleur doesn't fall off whenever the wheel is removed, as it obviously did.

    The nut on the wheel axle does most of the job of holding the derailleur to the bike when it is in use. This is obviously a very cheap bike. 5-speed, with index-shifting, suggests a cheap bike from the late 80s, or early 90s at best. Don't expect much from it.
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