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  1. #1
    Nemophilist
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    How do YOU set a Crown Race for Welding?

    Hey;

    Looking for ideas on setting a crown race as square as possible before welding. All that comes to my mind is to machine a die to a snug slip fit for the steerer that can be slid down and used as a square. It seems I'd like something theoretically a little closer than eye-balling.
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  2. #2
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    Eyeball is good enough, because of course you cut the race seat after welding/brazing.

  3. #3
    RCP Fabrication
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    28.6mm Paragon tube block with 1/4" of one end opened to 30.0mm

    Attachment 834920

  4. #4
    pvd
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    Hammer.

  5. #5
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by BenCooper View Post
    Eyeball is good enough, because of course you cut the race seat after welding/brazing.
    Agreed. I just slip it in place and braze it.
    mtbtires.com
    The trouble with common sense is it is no longer common

  6. #6
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    Grease, flathead screwdriver, hammer....done

  7. #7
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    Quote Originally Posted by Sprocking Crail View Post
    Grease, flathead screwdriver, hammer....done
    I think we're talking about the crown race seat, that gets welded/brazed to the steerer tube. Not the crown race that the bearing sits on from the headset.

    Hey, good question TM. Usually I lathe these after welding, its a very light skim and this squares it up. I braze mine, but I see a lot of manufactured unicrown forks are Tigged on the outer side. Cast crowns used on road bike forks are integral with the crown itself so you machine up afterwards from brazing. To keep the seat square when setting up, slip a squared over-sized tube down the steerer and tack the outer edge, remove tube and weld up, you will be close.

    Eric
    If I don't make an attempt, how will I know if it will work?

  8. #8
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    I think we're talking about the crown race seat, that gets welded/brazed to the steerer tube. Not the crown race that the bearing sits on from the headset.
    Yup - I do the same, well, I braze it on, do a rough cut in the lathe, then finish off with a Park crown race cutter to get it spot on.

    But since it's getting the cutting operations after welding/brazing, it's not necessary to be obsessive about getting it straight to start with.

  9. #9
    pvd
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    If you can put the fork into a lathe (like I do), why would you use the Park cutter? You can do far better with the lathe.

  10. #10
    Nemophilist
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    My solution;

    A good way of making use of one of those little slugs of bar stock that are too small for anything else.
    Attached Images Attached Images  
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  11. #11
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    Quote Originally Posted by pvd View Post
    If you can put the fork into a lathe (like I do), why would you use the Park cutter? You can do far better with the lathe.
    My lathe isn't big enough for a complete fork. So my fork procedure is:

    Braze crown to steerer
    Rough cut crown in the lathe
    Braze in fork blades
    Send off for paint
    Final cut with Park cutter to remove paint traces and get final crown diameter and face.

  12. #12
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    Quote Originally Posted by TrailMaker View Post
    My solution;

    A good way of making use of one of those little slugs of bar stock that are too small for anything else.
    I guess when you see this, an old H/bar Stem would become a handy tool.

    Eric
    If I don't make an attempt, how will I know if it will work?

  13. #13
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    I'm doing what BenCooper is doing.
    andy walker

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