Which fork? WP5060 50mm or WP 43mm usd?

Discussion in 'Thumpers' started by Queen of Spades, Feb 3, 2013.

  1. Queen of Spades

    Queen of Spades tall drink of water

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    Have a line on a set of 43mm USD forks off of a 2003 LC4 640e. Currently using the massive 50mm conventionals, but I"m finding a hard time locating heavier springs for these. Thinking I may have more options with the newer USD fork.

    Is the upgrade worth the headache? Will I lose much performance wise?
    #1
  2. Navin

    Navin Long timer

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    Try Cannon Racecraft for custom springs.

    Shouldn't be hard to get them. I've converted a few older KTMs to 48mm forks, you may need to weld steering stop threaded rod to the frame, might need new caliper too. The 50mm forks are very smooth, I had decent 43s on a 2002 520 but the 50mm were smoother IMO.

    http://www.cannonracecraft.com/
    #2
  3. Queen of Spades

    Queen of Spades tall drink of water

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    Thanks, I do see a listing for the 99 with 50mm forks.
    #3
  4. Queen of Spades

    Queen of Spades tall drink of water

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    #4
  5. Queen of Spades

    Queen of Spades tall drink of water

    Joined:
    Mar 20, 2009
    Oddometer:
    1,485
    Location:
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  6. Navin

    Navin Long timer

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    DS1434 username at ktmtalk is awesome for KTM suspension and really affordable too. His shop is Protune Suspension in Oh. PM me if you want to use me as a reference.
    #6
  7. Queen of Spades

    Queen of Spades tall drink of water

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    Thanks - I think I need to focus on getting the springs dialed before looking at revalving. I cannot find the stock spring rates anywhere for this bike.
    #7
  8. bmwktmbill

    bmwktmbill Traveler

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    Cannon can test your old ones for rate and sell you what you need, did it for me on the fork springs if I remember correctly.
    bill
    #8
  9. rz35027

    rz35027 Been here awhile

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    KYB Twin chamber fork springs are a very close fit, you may have to cut the black plastic spacer to the appropriate length, or use ABS pipe...

    05-07 450 Yamaha
    06-07 KXF 450

    The 450's have .47 rate springs.
    #9