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  1. #1
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    cutting a 1" threaded fork

    im in the middle of a build up that im doing and the fork im using for this road bike is a bit too long.

    I have added a couple small spacers and want to cut the fork down at this point.
    I have measured with the fork installed and it looks like ill be cutting 3 to 4 threads above my top spacer. I think this will allow for my top lock nut to thread on just the right amount without bottoming out.

    Are there any guidelines to this or tricks?

    I was a LBS yesterday and they wanted $20 to cut off the fork which seemed a bit high considering all they have to do is put the proper jig on there and hack it off.

    Im thinking that ill leave an old bearing race threaded on an the right height and use that as a guide and then cut it off that way. When i thread off the old race im hoping that cleans up the threads enough to thread on my equipment.

  2. #2
    Mad bike riding scientist cyccommute's Avatar
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    Quote Originally Posted by scale View Post
    im in the middle of a build up that im doing and the fork im using for this road bike is a bit too long.

    I have added a couple small spacers and want to cut the fork down at this point.
    I have measured with the fork installed and it looks like ill be cutting 3 to 4 threads above my top spacer. I think this will allow for my top lock nut to thread on just the right amount without bottoming out.

    Are there any guidelines to this or tricks?

    I was a LBS yesterday and they wanted $20 to cut off the fork which seemed a bit high considering all they have to do is put the proper jig on there and hack it off.

    Im thinking that ill leave an old bearing race threaded on an the right height and use that as a guide and then cut it off that way. When i thread off the old race im hoping that cleans up the threads enough to thread on my equipment.
    That's the way you do it. However, is it really worth it for 3 or 4 threads? At 24 threads to the inch, that's around a 1/16 of an inch you are taking off...pretty small. I'd look for a thin washer to take up the space and not hassle with cutting it off.
    Stuart Black
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  3. #3
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    no it is 1+ inches too tall. I just want to be sure when i cut it i leave 3 to 4 threads on the top so i can thread my top nut on just right

  4. #4
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    hmm...how high is too high with spacers? with my top cone threaded on where it needs to be to secure the bearings i still have 1 inch sticking above that or 25.5mm. Would it be entirely wrong for me to add 20mm worth of spacers here? Seems like alot.

  5. #5
    Mad bike riding scientist cyccommute's Avatar
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    Quote Originally Posted by scale View Post
    hmm...how high is too high with spacers? with my top cone threaded on where it needs to be to secure the bearings i still have 1 inch sticking above that or 25.5mm. Would it be entirely wrong for me to add 20mm worth of spacers here? Seems like alot.
    Adding spacers shouldn't be an issue. Threadless headsets can have huge amounts of spaces...2 to 2.5"...without too many problems. Most of those forks, however, are 1 1/8" diameter which are stiffer then 1" steerers. 20mm isn't that much. Many touring bikes with cantilever brakes have hangers that are nearly that thick.

    By the way, you want to undercut for the top nut, not leave extra thread. The nut should bottom out on the upper race/spacers and not on the steer tube. You couldn't get proper compression on the headset otherwise.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  6. #6
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    yes....undercut. THats what i meant. I count about 4 threads in my headset lock nut so my plan was to cut leaving 3 threads showing and praying that was just right

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