21" spoked front wheel on a F650GS?

Discussion in 'Parallel Universe' started by Oz-Strom, Sep 8, 2010.

  1. Oz-Strom

    Oz-Strom Still trying

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    Has anyone done this for improved dirt performance Also anyone fitted an 18" rear?

    I did this on my Aprilia Pegaso Trail, and like the fact that I can swap the std road wheels for the dirt wheels with knobbies for when I go serious ADV riding. I am considering this bike as a replacement.

    Thoughts and recommendations please?

    Thanks
    #1
  2. LukasM

    LukasM Long timer

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    Marky did it, there is a thread with lots of pictures. The front from an F650 single (Dakar version has 21" front) will bolt in with the twin spacers, just flip it around to get the brake disc on the right side.

    The 17" rear from an F800GS will bolt right in as well. You can also make a KTM 950/990 18" wheel fit, but it will require some custom spacers and an adapter plate for the brake disc. Not quite finished with mine yet, but it's from a 950 Super Enduro and has a super strong 2.5" wide Dirt Star rim.


    [​IMG]
    #2
  3. elijahl2

    elijahl2 Midlife BMW crisis

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    Good info. I'm thinking about doing this as well to my 2010 F650GS Twin. I'd like to hear more reports on it first before dropping the cash for it. Thanks for the post and keep them coming.:clap
    #3
  4. DakarboySA

    DakarboySA Adventurer

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    Do you guys know if its possible to put 21'' dakar front rim on a f650 twin :ear Cheers.
    #4
  5. Mike.C

    Mike.C Stelvio Dreamer!

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    Woody can now make one.

    Be aware that RAD makes these hubs from Woody's initial suggestions and design. Under no circumstances would I ever buy them from RAD as they modified the bearing design from Woodys' specs and there have been 4 complete failures that I know of, we evaded failure by some diligent pre flight inspection and after much investigation Woody discovered RADs' un documented and badly executed alterations to his design.

    Woody now gets the hubs from RAD and re specs them back to his original and much more robust design. If you want to see them in the flesh, PM me.


    Hmm just noticed you wanted a 21", ours are standard size but I see no reason why Woody couldn't lace a 21" rim onto the hub. Then the only difficulty might be clearances.


    <a href="http://www.flickr.com/photos/57523448@N08/5397755432/" title="Sal chickened out 3 by Mike_Sal, on Flickr"><img src="http://farm6.static.flickr.com/5098/5397755432_f2b4833c3a.jpg" width="500" height="375" alt="Sal chickened out 3" /></a>
    #5
  6. markymcd

    markymcd Been here awhile

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    I've used the f650gs single front wheel (it's a 19") and had woody build me a rear from a 800gs hub and Exel Takasago rim. I stayed with the same size as I'm vertically challenged but check out "A"'s thread. He started with the 650 twin and put a KTM front end on and i'm sure it's an 18" rear. Not 100% sure if the Dakar front will work but take a look at the schematics on BikeBandit and see if the 19" GS and 21" dakar have similar hubs and brake rotors.

    I'd be a little concerned about putting a 21 on the front with the existing forks. there might be clearance issues with full fork compression.

    I've done a few more mods since this photo... 2" rox risers. painted lower panels charcoal. removed front fender and added upper rear 650 single front fender. Tail tidy is next.

    cheers,
    Mark

    [​IMG]
    #6
  7. RBlake

    RBlake n00b

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    I bought a second set of wheels. Mounted K60 Heidenau tires with a 42 tooth sprocket on the rear.

    I can change my wheels between dirt/adventure and road/wet in a couple of minutes. The cast wheels are not nearly as durable, but my F650GS Twin is used more for commuting than anything else.

    If I do more dirt, I'll probably look for a lighter bike. For now I feel like I have everything I need on this bike.
    #7
  8. ebrabaek

    ebrabaek Long timer

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    I have a stock 21 in the flea market.....:evil:evil
    #8
  9. Juozaz

    Juozaz Juozaz F800GS Blonde

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    [​IMG]

    One from most important things for f650gs.

    Sorry friends, but how to import dirctly photos in this thread? Thank You, ebrabaek!
    #9
  10. ebrabaek

    ebrabaek Long timer

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    It appears your google link above is restricted. You need to host the picture on a online website. I use photobucket.com. It is free. Then you cross link it to this website. Takes a little to get used, but is fairly easy when you get started.
    #10
  11. Excite-Bike

    Excite-Bike Been here awhile

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    How would a 21" wheel and tire fit under a non-adjustable fender fixed to the forks that's meant for a 19" wheel and tire? :confused

    [​IMG]
    #11
  12. Reaver

    Reaver Outta Here

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    So a piece of plastic ends that plan?
    #12
  13. Excite-Bike

    Excite-Bike Been here awhile

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    Dunno, but it leads to believe that nobody actually has done it without completely replacing the forks as the guy with the red bike above did.
    #13
  14. Reaver

    Reaver Outta Here

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    Fairly common mod.

    No I don't have links......
    #14
  15. Excite-Bike

    Excite-Bike Been here awhile

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    So if an old F650GS Dakar or new G650GS Sertão front 21" spoke wheel is a direct bolt-on for the F650GS Twin then what is done to the fender to make room for the extra 2 inches? It gets moved up with some custom work? Replaced with some aftermarket fender? You need the fender from the donor bike?
    #15
  16. Reaver

    Reaver Outta Here

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    Extra 1".
    #16
  17. Excite-Bike

    Excite-Bike Been here awhile

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    Ah, true, 19" to 21" is just one inch since it is distributed half above and half below the axle, but anyway, how is that additional one inch accommodated for when it comes to the the fender?
    #17
  18. Reaver

    Reaver Outta Here

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    A 650 Dakar lower fender is a direct bolt on. Cheap too,






























    :hide
    #18
  19. Excite-Bike

    Excite-Bike Been here awhile

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    #19
  20. B_C_Ries

    B_C_Ries Long timer

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    21" tire should be thinner and not as tall from rim to edge so difference will likely be less then 1".

    My math has the 90-90 21" tire being 17.5mm closer to the fender than the 110 -80 19"
    #20