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Pinned Trail - Fitting USD Forks?

Discussion in 'Tech Tips' started by maelstrom, Dec 2, 2014.

  1. minimac

    minimac Active Member Premium Member Contributing Member

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    Lots of good info here. Thanks for posting!
     
  2. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    The offset of the MC22 is 35mm (absolutely true because I have the bike). Someone advised me that the offset for the ZXR250A is also 35mm. Maybe someone can clear this up. Might be different between the early and late ZXR's.
     
    Last edited: Sep 25, 2019
  3. Murdo

    Murdo The Good Doctor Staff Member Premium Member Ride and Events Crew Contributing Member

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    Have measured them at 35mm offset on ZXR250A 1989 build.
     
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    Last edited: Sep 27, 2019
  4. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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  5. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    Now that my front end is fitted, I updated the original post so that all 5 sections are finished.
    Cheers
    Blair
     
    Last edited: Nov 12, 2019
  6. ruckusman

    ruckusman Well-Known Member Premium Member Dirty Wheel Club

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    I dug out my copy Motorcycle Tuning - Chassis by John Robinson a week ago, and what do you know, there's a set of Spondon adjustable triple clamps pictured in there.

    The design is brilliant in it's simplicity

    Now potentially you could use the steering stem portion from the original triple clamps, coupled with a set of triple clamps which accomodate your desired USD forks with some careful cutting, drilling and tapping.

    One less variable which expands the possible choices that eliminates the chase for triple clamps with the same offset as OEM, or perhaps an adjustment to get another offset/trail number which might suit different tyre widths and profiles.

    It's figure 2.3 in this link

    https://books.google.com.au/books?i...page&q=john robinson adjustable forks&f=false
     
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  7. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    I used to have those books, oh well. If the clamps were solid billet it might be possible but I think you would have to go with welding and milling when using most OEM parts.
     
  8. ruckusman

    ruckusman Well-Known Member Premium Member Dirty Wheel Club

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    I may have a clever solution to that conundrum which should make it as strong as solid billet, if not stronger, and very accurate in the process, but you'll have to wait until I get the drilling and hacksawing done
     

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