Please explain the "Threadless" fork scenario for me!?

Discussion in 'Bicycle Repair' started by Motorbike Wanabe, Jan 1, 2010.

  1. I'm working on my second MB build and I want to make a chopper or a slightly chopped bobber. I have an old mountain bike that I'm considering using and so far, without checking, I believe it has a 1-inch steerer tube in it with a threaded tube for the bearings.

    I'm looking at some front forks ("-BK/) but I don't know what the whole "threadless" thing is about. So you mean there are no threads on the steering tube? How do you tighten the bearings? What about the handlebar tube? Does it just go into the steerer tube and tighten down? I want to do this right the first time. I guess it could be beneficial since you can move the upper and lower triple tree mounts to fit your application and then trim off the steerer tube, right? Please help!

    thanks for any enlightenment.

  2. professor

    professor Active Member

    The Trek I got last summer had that threadless deal.
    For height adjustment there are spacers, the thing has a pinch bolt that clamps the handlebar neck in place.The stem is quite large around, so it will not fit in other frames. The whole assembly is lighter than the old style.
  3. So, would I be able to go from what I have now to a "threadless" one? What would I need to do? Would the old bearings work in the new threadless forks?

    thanks for any insights.
  4. professor

    professor Active Member

    IF (and that is a big if) the fork top tube that goes into the frame is the same size, you would just assemble it. If the sizes are different, you need to remove that section of the frame and weld on one that fits.
    By the way, those threaded tubes seem to be in a couple of different sizes also.
  5. ocscully

    ocscully Member

    Here is a link to some good information on threaded and threadless headset/steerer systems. You are gong to find when it comes to suspension forks these days that there isn't much available with the older 1" steerers. You can still find very inexpensive entry level forks from some suppliers but when it comes to a really quality suspension fork 1" steerers disappeared in the middle to late 90's.

  6. Youngbird

    Youngbird Member

    On the threadless chopper forks, all you need do is assemble the unit(slide the stem through the steertube) slide the top "tree" into place and tighten it up. If the steer tube section is too long, use a hacksaw and shorten it. Make sure to leave enough for the headset....ezy pezy!