Yamaha forks on a BMW F650GS Dakar

Discussion in 'Thumpers' started by skibum_1260, Oct 23, 2008.

  1. WayneC

    WayneC Long timer

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    The lower yolk is the under side of the egg or in this case the black part the fork legs slide into at the steering head

    Dont be too concerned though at this stage, you can get by with a slightly twisted lower yoke, the GS is not too fussy with it and is not likely to exhibit bad handling. Mine is in that state at the moment

    It can be checked simply by placing a wide flat board on the fork sliders and see if it fits flat against both sides, if not loosen the yoke bolts push the bars left and right then tighten the bolts again and recheck. If it is twisted the board will not sit flat. I use a good piece of 1" particle board for checking such things, an old trick from long ago

    Now out Cobar way they use a tree fork to hold the front wheel while pushing on the bars.
  2. Hewby

    Hewby Been here awhile

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    Ok. Great good to know more. Also that its not totally urgent. Possibly another refill op in Peru when Huzar comes over for a ride if really needed. Thanks heaps. Will have it all checked at the shop when I get it to Bogota. Now on that note- must I find myself some transport!
  3. nomad5326

    nomad5326 Xventurous

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    Hey Hewby, I have the following parts if you need them:
    F650GS and F650GS Dakar forks (uppers pitted a bit and need buffing) but all lowers completely fine.
    Fork Brace intact
    Upper and lower yokes/triples as well.

    For sale in flea market but shoot me a pm and let me know what else you need. I can ship them out probably after Xmas/New Years when things are open. Cheers!
  4. Kainic

    Kainic Almost there

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    Any word on their setup?
  5. kubiak

    kubiak Long timer

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    has anyone tried to lower the yamaha forks besides sliding them up in the clamps? i have mine slid up in the clamps but i want another inch lower. i know you can have it profesionally lowered by shortening the parts but is there something i can do at home like cut a little off the spring?
  6. mattomoto

    mattomoto 2 wheels rule

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    Kubiak, you can usually shorten a fork my putting some travel reducing spacers in the fork. Usually on the dampening rods. We do this on mtb forks so probably pretty similar on moto forks. Will probably need to shorten the springs/pre load spacers I would think. Forks are pretty much the same in construction so I bet you could find the info pretty easy and you seem to be quite handy with tools judging by your projects. :wink:
  7. kubiak

    kubiak Long timer

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    yea i saw a little info on the internet but not sure which way to go yet. i will check more on the spacers like you are saying. thanks for the info mattomoto!
  8. LoJack

    LoJack Long timer

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    B.G., yo!
  9. kubiak

    kubiak Long timer

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    thanks for the info, im going to read up on it and see what its all about!
  10. mattomoto

    mattomoto 2 wheels rule

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    Yep, just like that :evil Good find JoJack.
  11. Clob

    Clob n00b

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    After a long wait already for a Radman Axle I have gone about getting one made. I am using the original spacer on the opposite side to the disc but now need to make up a spacer for the disc side to center the wheel in the forks. Its real difficult to work out the centre. Does anyone have the thickness of the spacer used in the Radman axle please?
  12. WayneC

    WayneC Long timer

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    Silly thought on the axle, looked at the 650x for other reasons and they have 220 mm fork spacing and a 20mm dia axle which screws into a "spacer sleeve" on the LHS

    It would seem you could use their axle & turn it down for the GS wheel, the spacer sleeve looks similar to the sleeve used in the Radman kit. Would take a bit more into and measurements but may be worthwhile

    In addition they have some interesting brake cable guides and ABS mounts which could be used/adapted
  13. WERA456

    WERA456 Been here awhile

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    I use a piece of angle iron. If it rocks then it needs pushing or pulling. if the four points sit without rocking then it is good.

  14. WayneC

    WayneC Long timer

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    Can those who have done the conversion measure the distance from the centre of the yoke post to the front edge of the upper yoke ?. I need the measurement to complete a diagram for the ignition switch mount

    I know there are variations between some of the yokes which have been used so the more measurements the better to work out the max and min values likely to be encountered

    Would greatly appreciate any assistance and measurements posted
  15. Aquatic

    Aquatic Long timer

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    I have a Dakar top clamp and a YZ top clamp.
    I can help you out by Tuesday with measurements if that suits.

    I need to do it as I am busy building custom clamps for myself anyway. Just haven't had the time to get to it.
  16. WayneC

    WayneC Long timer

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    Thanks is appreciated, and no I am not in an urgent hurry
  17. Barnman

    Barnman Been here awhile

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    Not easy to get a quick and accurate measurement, but it looks about 35mm with a tape measure on mine Wayne.

    [​IMG]

    [​IMG]
  18. Dan Alexander

    Dan Alexander only happy when sad

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    Will someone please once and for all make a top clamp that we can buy that works with the Yammy forks and OEM ignition. I've got a set of forks waiting :deal

    :evil

    Plus it has to have the possibility of mounting a damper.
  19. Aquatic

    Aquatic Long timer

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    What brand damper? Iow what configuration of mounting
    holes?
  20. Schlug

    Schlug JockeyfullofBourbon

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    put something on and stay in that position.

    When I went to my local renown suspension shop and described what I was doing. The fellow there had rebuilt forks with heavier springs for BMWs but wasn't sure why. After I explained everything he said, "do you want us to shorten the forks up to improve the geometry of the BMW?" Wow, never heard of that on any forum. I said, 'can we?'

    Well, he had to order fork springs at 6.0 for the weight of the bike, my weight and luggage. He said he could order than shortened for a bit more dosh.

    So I'll let you know what happens. We're shortening them 2". I had no idea how short to go since no one has ever mentioned this as possibility. It's only a matter of changing the fork springs out or they can even space the shorter spring if I don't like it.