640 Adventure Fork Stiction

Discussion in 'Thumpers' started by Dolly Sod, Mar 3, 2013.

  1. slackmeyer

    slackmeyer Don't mean sheeit. .

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    I haven't had to replace seals yet in either my 950 (60k miles) or 640, but I find it interesting that people on this thread don't seem to like the new skf seals. In the 950 part of this forum, everyone says the skf seals are the hot ticket to reducing stiction and making the bike perform better. Maybe they are a bit looser than the NOK seals. In any case, I think that seal stiction on most forks is a pretty minor player on the fork action, this binding must be something else going on. . .
    #21
  2. gunnerbuck

    gunnerbuck Island Hopper

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    I'm thinking that with my tubes being well used {worn down a bit}, that the already loose fitting SKF seal does not grab them with enough pressure compared to if they were new... I find it strange that a five year old used seal {BR6812E} that likely has 50,000 miles on it will out perform the new unit and not leak a drop... With the SKF seal every time the fork travels up and down it leaves a deposit of fork oil behind, yes less stiction but soon your fork action will change with the dropping oil level... The SKF on the left side was dripping off the bottom of the fork after a 300 mile ride...
    #22
  3. Sparrowhawk

    Sparrowhawk Long timer

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    Different colors probably mean different materials. Black=neoprene, green=butyl? The problems may not be with the SKF brand. WP might specify a particular polymer for their seals in a standard size resulting in the bearing supply items failure with OEM success.

    Sent from my SCH-I535 using Tapatalk 2
    #23
  4. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    My forks have around 28,000 miles on them. The SKF seals were definitely a bit more snug than the 2 year old NOK seals I took off. :dunno

    We'll see, I'll keep an eye on the new seals and see what happens. I'm hoping I don't have to tear into the forks again for a while.

    Just got to get power run up to my GPS, buy a Wolfman Enduro Tank Bag and braze up some soft luggage standoff's and I should be good for the summer. :ricky
    #24
  5. gunnerbuck

    gunnerbuck Island Hopper

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    I guess I better quit plugging up your thread and post in the fork rebuild thread...

    My SKF seals were quite snug going on, I use a plastic bag to slide them over the sharp corners to prevent damage and they were as stubborn as any.. Slackmeyer mentioned that the 990 folks liked the SKF for the reduced stiction they provide so I assumed that they do not grip as tight to the tubes as others.. This could be somewhat true because their garter springs are half the thickness of those on the WP seals...

    Maybe like sparrowhawk mentioned, the green color in your seals could be due to construction from a different more slippy and more compliant compound than NOK... The NOK designation written on the black seals indicates that it is made with an anti stiction rubber compound...

    These seals are supposed to be chemical proof, but maybe my assembly grease is whats killing these seals ?

    Hopefully your forks are good for the long run so you can concentrate on your other projects and riding... If my old seals give out I can always pull the forks off my other bike to use until my next trial replacement set of seals arrive...
    #25
  6. bmwktmbill

    bmwktmbill Traveler

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    I called WP today and talked to Dan, the service manager.

    Tel # 336-903-0363

    http://wpracingusa.com/

    He gets his seals from KTM and has NOK and SKF depending on what you want and as has been said SKF offers less stiction.

    The frikkin seals are $20usd each.
    I told him I thought that was robbery and he agreed.

    We need help.
    bill
    #26
  7. LukasM

    LukasM Long timer

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    The new(ish) SKF seals that everybody raves about are green, regardless of whether you get them OEM from KTM or somebody else. I spoke to a WP engineer at the factory in Mattighofen and he said they are much better than their own seals, NOK, or any others, both in reduced stiction and longer service life.

    So Gunner, yours are not the right ones.
    #27
  8. gunnerbuck

    gunnerbuck Island Hopper

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    I have also done a bunch of research, and yes, the SKF seals I have are the previous generation and while they are identical to the newer seal in design, the material that they are made of is not the same... The newer SKF seals {green} are made of a self lubricating low stiction material that is a big improvement over the NOK rubber that is commonly used in many brands of seals {including W.P.}...

    I always like to purchase the consumables in bulk, so I ordered 3 sets of these SKF seals, this is one time where I wish I hadn't...
    #28
  9. bmwktmbill

    bmwktmbill Traveler

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    Does the green SKF seal have a number to identify it?

    Is it available to the general consumer?

    When I spoke to the WP USA guy he said the NOK's outlast the SKF's and because of that he sells more of them.

    I have a note in my records that the original seal in my '02 Adventure was a
    KACO QHWA 48, 57.7,9.5/10.3 SGFOL, the dust seal was a KACO WP QAS48,62.2,11.8 AGOL

    http://www.kaco.de/en/


    bill
    #29
  10. gunnerbuck

    gunnerbuck Island Hopper

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    Interesting, I do a search on a Kaco seal in a size for the 640 and an Athena seal comes up: http://translate.google.ca/translat...a=X&ei=UK9fUYXtBMOaiQLWkIDYDA&ved=0CFUQ7gEwBA
    #30
  11. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    You can get them at Slaven Racing..

    http://www.slavensracing.com/shop/fork-seals-by-skf-for-wp-ktm-husaberg

    It's almost cheaper to buy the whole maintenance kit than it is to buy a pair of seals and wipers from Slaven.
    #31
  12. bmwktmbill

    bmwktmbill Traveler

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    Boon,
    They are still too much IMHO.

    Anyone with a way to ID the seal so my bearing house can go on the search?
    bill
    #32
  13. LukasM

    LukasM Long timer

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    The SKF number on the box is Kit48W-COD.10008162152.

    Note that this gets you ONE seal and ONE dust scraper, so you'll need two of them.

    I also think you will find that the KTM SXS kit will be a far better deal, especially if you get a good discount on KTM parts.
    #33
  14. bmwktmbill

    bmwktmbill Traveler

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    Lukas,
    I don't know anything about the KTM SXS kit, do you have a part number and a description.
    Thanks, bill
    #34
  15. LukasM

    LukasM Long timer

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    I am talking about the KTM SXS fork service kit mentioned several times in this thread. List price in the US is $100 for the whole thing (in Europe we pay $170!! :puke1), and it's easy to find good discounts on OEM KTM parts.

    SXS KTM WP 48mm Service Kit


    [​IMG]
    [​IMG]




    Brand:
    KTM
    Code: R14020
    #35
  16. bmwktmbill

    bmwktmbill Traveler

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    Thanks Lukas,
    I get it now.

    As you said the kit is a deal.
    Still a little unclear if all the seals and bushings are the same for the '02 vs. the 03 fork but I am under the impression that everything interchanges.
    bill
    #36
  17. gunnerbuck

    gunnerbuck Island Hopper

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    Hi Bill,
    Your forks are the same as Boon Boonis so you could perform the same mods as he did to make the kit work...
    #37
  18. bmwktmbill

    bmwktmbill Traveler

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    Hey gunner, Lukas,
    Went ack and read the thread carefully.

    It's all there.

    My brain was asleep...or stunned.
    Snowing here...and this.

    KTM Central on wheels.

    http://advrider.com/forums/showthread.php?t=847293


    bill
    #38
  19. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    Got to spend part of the week riding this thing up and down mountains. :clap

    The big old KTM eats rocky dirt roads for breakfast. :ricky

    [​IMG]

    I don't have any photos from the dirt roads because I was going too damn fast to slow down for a picture. :D

    WVA is awesome.
    #39