F800GS Bitubo Fork Kit

Discussion in 'Parallel Universe' started by DockingPilot, Jun 1, 2009.

  1. Desert Dave

    Desert Dave Enjoying the moment

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    Jus curious, does Bitubo recommened doing it that way? Most (all that I've done anyway) forks require a special tool to put down to fork tube to hold the unit in place while I use a torque wrench to set the bolt. So far I've always been able to make a tool for this use out of things I've bought at a hardware store instead of buying one. Even if I can just get the bolt started an finger tight without it spinning (often no tool required) by the time I put a spring and the cap on there's enough tension to torque it to spec without it spinning . I'm guessing your way will be fine, but I'd rather not impact it (when putting it on) or overtorque it if I can help it.

    Your initial assesment sounds exciting and I can't wait to hear how you feel after getting in some good riding. Sounds like the dampning works like it should have from the factory (not locking on sharp hits) and the stiffer spring should avoid bottoming (another problem for me). This could be the solution.

    So basically now it works as good as any bargain Showa inverted forks from the mid 90s :lol3 Way to go Marzocchi!!!
    #61
  2. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Dave, yea, Im sure there is more than one way to do it and I'm also sure you know more than I on this.

    On the test ride, that was the BIGGEST thing I noticed right off the bat. No initial hit (shock) like before. Sucked it up imeaditly without throwing the steering off. I like them. You can order spring rates for you. Read the email I posted above from Bitubo regarding spring rates and rider weight.
    #62
  3. PackMule

    PackMule love what you do Super Moderator

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    I don't own an impact gun, but I was under the impression that you were able to set a "blow off" torque on them?
    #63
  4. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    I use an electric one Nate. I just just tap the trigger. You can get a good feel for it. You dont want to over torque it like Dave said. This is a light application. So it wont take much.
    #64
  5. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Dave the instructions simply say to tighten them. But not how to do that.
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  6. bubwould

    bubwould Redneck Hippie

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    Right on Frank, thanks for the report! Love the 800GS but the forks need some major improvement, gotta get some.

    I agree on the impact trick. It only takes a quick pulse of the trigger and it tightens right up. Done it myself this way and seen other, real mechanics:D, use the impact wrench as well. Its kinda a fail proof method due to the fact that the tube spins once its tight.
    #66
  7. Desert Dave

    Desert Dave Enjoying the moment

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    Sometimes I may go overboard, but that little click from the torque wrench always takes away any doubt if I did it right or not.

    I think we are pretty close on rider weight so there's a good chance your set up would work for me. And in all honesty I'm not worried about dialing in the suspenders like I would on a competition machine on a particular circuit where I won't stop if I think I can get it closer, I just want the darn things to work. Especially with a dual sport bike where good enough is usually the case considering the different extremes that we take them to.

    I'd imagine the rear end is going to feel awful on trails now that your front end isn't holding you back :wink:. looking forward to your shock report as well.
    #67
  8. bxr140

    bxr140 Flame Bait

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    That's good to hear. It seems to imply that they can set up the damping for rider weight...though only if you're out of their (somewhat large) range.
    #68
  9. bxr140

    bxr140 Flame Bait

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    In some cases, inserts allow you to use two different weights of oil, providing more versatility with tuning.

    If they're *completely* sealed, the fluid in the tubes might just be there for the 'air spring' factor? :ear
    #69
  10. PackMule

    PackMule love what you do Super Moderator

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    2 wt fork oil?
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  11. The Griz

    The Griz Long timer

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    Actually, 5wt comes with the kit.
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  12. jeffchri

    jeffchri Been here awhile

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    Gah - dang. AFTER this diet I'm on is over, I should be at the very very very teensy top end of that range ... not great.

    The guy at Hardan's (nice guy, I agree - crotchety in that funny way) said it takes AGES to get stuff from Italy, so I'm not super-excited about the prospect of negotiating a custom kit from the Bitubo engineers, but I guess it's worth a try.
    #72
  13. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    bxr, they are sealed, so it just lubes the bushings and seals and provides cushion on comprssion. So I have been told.

    Griz, no it's 2 wt Synthetic. At leas thats what it says on the bottle. :dunno
    #73
  14. huckleberry

    huckleberry BACK ROAD BOMBER

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    so whats up with your shock docking pilot? pics? am very interested in that!
    #74
  15. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Hey Huck,
    Ill take pics as soon as. It is really sweet though Ill tell you that. The shock I have no doubt will be a winner.
    #75
  16. The Griz

    The Griz Long timer

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    Weird, says 5wt on the bottle in this pic. They gave you 2wt instead?

    [​IMG]

    Either way, that's some thin oil! Probably a testament to why the kit is working so well for you. Thinner oil moves through cavities faster. Seems like they designed the springs and cartridges around this lighter oil perfectly. Makes sense.
    #76
  17. bxr140

    bxr140 Flame Bait

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    The "cushion on compression" must be their way of describing the 'air spring'--the compression of the air in the gap between the oil and the top of the fork.

    If the units are completely *sealed* though, that begs the question...how do you rebuild them? Fork oil really should be changed every 10-15k miles at most.
    #77
  18. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Griz, the oil does not flow through any cavities. When I get Ill double check the wt.

    bxr, the oil is easy eough to change. The gas inside the units Im not sure what happens there.
    #78
  19. bxr140

    bxr140 Flame Bait

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    <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>

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    I'm talking about the oil inside the cartridges themselves, not the stuff you poured into the fork tubes. The nitrogen charge in there is only to prevent cavitation of the oil that's also in there--similar to a rear shock. The oil is the stuff doing the damping, not the gas charge. <?xml:namespace prefix = v ns = "urn:schemas-microsoft-com:vml" /><v:shapetype id=_x0000_t75 stroked="f" filled="f" path="m@4@5l@4@11@9@11@9@5xe" o:preferrelative="t" o:spt="75" coordsize="21600,21600"><v:stroke joinstyle="miter"></v:stroke><v:formulas><v:f eqn="if lineDrawn pixelLineWidth 0"></v:f><v:f eqn="sum @0 1 0"></v:f><v:f eqn="sum 0 0 @1"></v:f><v:f eqn="prod @2 1 2"></v:f><v:f eqn="prod @3 21600 pixelWidth"></v:f><v:f eqn="prod @3 21600 pixelHeight"></v:f><v:f eqn="sum @0 0 1"></v:f><v:f eqn="prod @6 1 2"></v:f><v:f eqn="prod @7 21600 pixelWidth"></v:f><v:f eqn="sum @8 21600 0"></v:f><v:f eqn="prod @7 21600 pixelHeight"></v:f><v:f eqn="sum @10 21600 0"></v:f></v:formulas><v:path o:connecttype="rect" gradientshapeok="t" o:extrusionok="f"></v:path><o:lock aspectratio="t" v:ext="edit"></o:lock></v:shapetype><v:shape id=_x0000_i1025 style="WIDTH: 23.25pt; HEIGHT: 23.25pt" alt="0" type="#_x0000_t75"><v:imagedata o:href="http://s3.amazonaws.com/advrider/Norton.gif" src="file:///C:\DOCUME~1\randolpb\LOCALS~1\Temp\msohtml1\01\clip_image001.gif"></v:imagedata></v:shape><o:p></o:p>
    <o:p></o:p>
    Just thinking out loud, but in addition to the spring tuning mentioned already, the other reason (perhaps the primary reason?) you put oil in the fork tubes is to cool down the cartridges. I'd surmise that the weight of the oil is largely irrelevant. <o:p></o:p>
    #79
  20. PackMule

    PackMule love what you do Super Moderator

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    :nod

    I'd wondered about the unit servicing, too... :ear
    #80