Yamaha forks on a BMW F650GS Dakar

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

  1. JDRadman

    JDRadman Moto Head

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    It is real!
    We have completed the prototype and have the whole set up mocked up on the bike and worked and looked perfect.

    We have some pictures that we hope to have posted soon. We will work up pricing and get that information out to everyone early this week.

    It is going to be 3 pieces:
    1. Hanger
    2. Axle spacer and nut
    3. Brake line
    I have a complete writeup available for any one that wants one.

    If you have contacted me and said you want a set-up I will PM you in the next few days...

    Stay tuned for pictures...

    Rad
  2. notmybikemodelname

    notmybikemodelname KOTW is a myth!

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    No brake line for me, just 1 and 2.
  3. Aries71

    Aries71 Adventure seeker

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    Can't wait to see the final product, I'm still interested for sure. I may or may not go for the brake line, since I have ABS, I don't know if it'll fit, may be too long.
  4. Brute

    Brute Melbourne , outer east .

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    Axle spacer & nut only . Which axle do you use , Yamaha or BMW ?
  5. JDRadman

    JDRadman Moto Head

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    I am building a complete new axle and nut out of stainless.. It is sort of a hybrid of the the two and needs to take into account the incompatible BMW wheel bearings (smaller) with the Yamaha fork end (larger).

    So it is a one-off two piece unit but works well.

    Rad
  6. JDRadman

    JDRadman Moto Head

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    I don't know what the ABS line dimensions are. If you can't have one made locally I can probably make a copy of yours with the extra length needed to follow the rather unique routing of the earlier 46mm Yamaha forks.

    Rad
  7. farkleface

    farkleface ridin dirty

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    full kit for me!!:clap
  8. Brute

    Brute Melbourne , outer east .

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    Pics ???
  9. JDLuke

    JDLuke Ravening for delight

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    Money's a bit tight, but I believe I'm in for a full kit, if the ABS fitting is right.:thumb
  10. JDRadman

    JDRadman Moto Head

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    Well not being a big ADV Poster (mostly lurker) I haven't posted any pictures before so here goes.

    EDIT I will get this cleaned up soon>>>

    As noted we mocked up the prototype last weekend. I had the brake line (non abs) installed for cable routing purposes and you can see the whole package here. Sorry for the delays but the day job has been getting in the way for both me and my buddy doing the machining.

    Here is the font view so you can see the brake line routing...it works out nice. You guys with ABS will have to help me out by sending me a sample if we need to build one.

    [​IMG]

    This shows the Caliper hanger in place with the caliper and the brake line.

    [​IMG][​IMG][​IMG]

    And here is the hybrid axle that I made to mock up the prototype. I merged the OEM Yammie with the BMW to have a working model. It works great but the new one is stainless steel. It should be here early next week.

    [​IMG][​IMG][​IMG]

    So there you have it...the working prototype.

    I will have 4 complete units available next week. I still haven't got a firm price for them but I will post it as soon as i do.

    When I get the pricing, I will give the "first right of refusal" to those that contacted me in that order. If we have enough interest we will make another run if necessary

    Sorry for the delays but real life keeps getting in the way of fun...I am going to have to work on that...

    Rad
  11. notmybikemodelname

    notmybikemodelname KOTW is a myth!

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    I began working on the tank design/plug today. Also started the rough measuring and laying out of the shape of the new rear tank in blue. New seat shape is also mocked up and extends up onto tank to reduce those nad ruptures.
    [​IMG]
  12. WayneC

    WayneC Long timer

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    For those contemplating rear suspension upgrade to match the front, a little while ago I measured clearances on the rear end for an entirely different reason & went back & looked at the figures today

    With the stock rear shock length there is 20mm clearance from the tyre to rear guard (multiple points) at maximum compression travel of 210mm

    This would probably come down to even less with a 130 knobbly rear tyre as opposed to the 120 stock width tyre

    So any increase in rear suspension travel will definitely require adding length to the rear shock

    Can anyone else confirm the measurements I took which were done on my 02 Dakar, I had a Mitas 130/80 17 E07 semi road tyre fitted at the time of the measurements
  13. notmybikemodelname

    notmybikemodelname KOTW is a myth!

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    Not necessarily, most of the time when increasing rear travel you're looking for added sag as well for handling the really rough stuff at high speed. When I get around to doing mine, I'm looking for one inch of added height and 2-3 added inches of sag. This exactly why the Ohlins that is sold by TT has 300mm of travel. Most of the new travel is in the sag where it's stored until you need it:clap
  14. WayneC

    WayneC Long timer

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    Yes, familiar with the sag aspect, thought I would throw up the clearance info from my measurements for cross checking & ensure all were aware there was little upper clearance
  15. Brute

    Brute Melbourne , outer east .

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    Nice work Radman . The package looks good . Interesting you`ve gone with stainless rather than 4140 for the axle .

    Notmybikeetcetcetcetc . Looks like a big project you`re undertaking . Hope you come up with the bike BMW should have made .
  16. notmybikemodelname

    notmybikemodelname KOTW is a myth!

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    That's what I'm going for:freaky
  17. Aries71

    Aries71 Adventure seeker

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    The setup looks great RAD!! :clap

    The brake line setup on an ABS bike is like this: it's in two parts; brake line goes from the caliper to about midway on the steering tube to a little "manifold" (for lack of a better description) where it branches out to the ABS unit. Then from the ABS unit back to the steering tube "manifold", up to the master cylinder via a second brake line to the handlebar.

    So 2 brake lines basically, but the one of concern for this mod would be the one from the caliper to steering tube. If you were to make one, you would have to measure from the caliper to about midway up the steering tube give or take 1 inch. Also the banjo fitting at the steering tube end would have to have a 45 deg to it to mount to that "manifold" properly without any interference with the fork (It comes in from the back of the fork).

    Just curious, any particular reason you went for the old Yamaha setup instead of the setup on Notmybikesname? It seems it would be a little more straight forward... just wondering.
  18. WayneC

    WayneC Long timer

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    Aries71

    Why not take a pic of the ABS joining point at the steering head, that would make it easier to understand & estimate length & spec the banjo fitting

    Re use of the Yamaha wheel, bearings are some 30 to 40% lower in strength when you check the specs and braking perfomance for the road is down, an oversize disc could be made & used with the new hanger & BMW caliper but expense comes into play
  19. JDRadman

    JDRadman Moto Head

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    {Just curious, any particular reason you went for the old Yamaha setup instead of the setup on Notmybikesname? It seems it would be a little more straight forward... just wondering.[/quote]

    About the brake line routing. I decided to use the 46mm 98-03 Yamaha forks because they are so much more plentiful and therefore less pricey. The 46mm front shields don't have the cable attachment in the same configuration as the later models but that could have been over come pretty easily. The clasping comes from the lower leg and the upper attachment is just a guide on the 03.

    The big issue is that cable routing in front of the upper triple just isn't possible with the standard faring in place. Note that on Rob's bike, he doesn't use the stock faring and his body work is very open allowing for the traditional dirt bike routing of the brake cable. But ya gotta love what he has done to his ride.

    I think the ole fashion Yamaha routing will work pretty well on this bike. The cable in my pic is not finished out. It will get some additional coverings to make it less abrasive on the fairings and other soft parts. I will also add a bit more rigidity to the cable where it sits in front of the lower shields to keep it snugged in and out of harms way. Then add the Yamaha OEM guard at the bottom and cover the silly wrap that they did around the axle. It will be a very tidy install.

    Stay tuned. Now I can actually post pictures and next week, I have some time scheduled away from the office to get this phase of the project done.
  20. JDRadman

    JDRadman Moto Head

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