640 ADV Forks

Discussion in 'Thumpers' started by The Misinformant, Nov 4, 2007.

  1. The Misinformant

    The Misinformant What road?

    Joined:
    Jun 22, 2004
    Oddometer:
    350
    Location:
    Adelaide, Australia
    Has anyone changed the springs themselves on the 4860WP forks? Is there any special tools required and is it a reasonable easy job?

    Have found a set of .46 WP springs out of a 06 640 to replace my .44 WP springs in my 03 640 ADV - which we think are a direct swap.
    #1
  2. Laromonster

    Laromonster Vesperado !

    Joined:
    Jun 28, 2004
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    Sviland
    Arent the 03 forks 43mm and the 06 48 mm ?
    #2
  3. The Misinformant

    The Misinformant What road?

    Joined:
    Jun 22, 2004
    Oddometer:
    350
    Location:
    Adelaide, Australia
    My owners manual says 4860, so I assume they are 48's. Let me look in the shed.
    #3
  4. GodSilla

    GodSilla I did that.

    Joined:
    Sep 21, 2006
    Oddometer:
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    The '03 model got the hi-flow head and the rally 48mm forks, from memory.
    #4
  5. The Misinformant

    The Misinformant What road?

    Joined:
    Jun 22, 2004
    Oddometer:
    350
    Location:
    Adelaide, Australia
    Yep books say 48mm. Can't measure them tonight as it not here. Bloody squids!
    #5
  6. Para504

    Para504 Spam, Spam, bacon & Spam!

    Joined:
    Sep 5, 2005
    Oddometer:
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    Cow Hampsha, USA
    My '02 has 48mm (measured them to be sure) as well. The literature is notoriously wrong!
    #6
  7. Luke

    Luke GPoET&P

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    It's pretty easy, there was one special tool that I needed. In order to separate the top cap from the bottoming bumper, I needed to grind down a wrench so that it was thin enought to slip onto the flats on the bumper's nut. I think it was a 15mm wrench.
    #7
  8. Zerodog

    Zerodog Long timer

    Joined:
    Jun 9, 2006
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    Location:
    SLC, UT
    Yes the 03 has 48mm forks. They are pretty much the same fork as the MX bikes. They just have a slightly shorter stroke on the cartridge. That is why they take the shorter springs. The 510mm springs will also work if you remove all the preload spacers except the thinest one. They are also the same interally as the 07 640. The .46 will most likely still be too light. But it will still be an improvement.
    #8