F800GS Bitubo Fork Kit

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

  1. johngil

    johngil Reseda, CA

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    Were there any options for spring rates?
    Good suspension w/ the wrong springs could be a waste.
    Javier (trailtrick) says he may have an answer for me.
    #21
  2. The Griz

    The Griz Long timer

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    No, and they are linear rate springs. But that is also why they have a preload adjustment. To suit a wide range of weights.
    #22
  3. Bigem

    Bigem Long timer

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    Not available in Australia yet so I'm sticking in a set of Progressive springs and gonna play around with oil weights. If it makes a noticable difference I will let you know.
    #23
  4. RAD800

    RAD800 Been here awhile

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    I might try giving them a call and see if they'll ship, no point waiting for them to be distrubuted here or being spoke to like a muppet by local retailers.:becca
    #24
  5. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    In all honesty though, I rode the stock suspension pretty hard this weekend at a dual sport event and Ill tell ya, it wasn't bad! Much better than my TE610 stock forks and on par with my 950A. I was able to ride the bike very fast through some rocky sections. I was surprised. not perfect by any means, but certainly as bad as I expected. It didnt warrent a thread "800GS good bike but poor suspension" imho.
    If I hadnt already bought a shock and fork kit, I just might have considered leaving it alone. Maybe.
    The shock anyway.
    #25
  6. The Griz

    The Griz Long timer

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    +2 I've ridden my F800GS offroad numerous times now, and have not been "disgusted" by the suspension as others have. For me it works just fine, but maybe that's because I weigh 185 lbs. This bike is set up from the factory for a 187 lb rider. States it in the manual as well. The most I think I'm going to do is put on that Hyperpro rising rate spring set.
    #26
  7. M N B

    M N B would rather be riding

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    You're kidding? Why make a high end, adjustable cartridge and leave out the most critical part of suspension. Preload does not sufficiently compensate for weight. Proper spring rate is just as important. With inadequate spring rate, you'll bottom out much easier when sag is properly set.


    Maybe I'll just get the front resprung and replace the rear shock (I don't think it can be resprung?)
    #27
  8. Desert Dave

    Desert Dave Enjoying the moment

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    What critical part is left out? :scratch

    Are you referring to the fact that it's a linear spring? (or did I misread your post?)

    Of course you're correct in needing proper spring rate, and preload is important for setting sag in either linear or progressive.
    #28
  9. The Griz

    The Griz Long timer

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    Actually, the fact that the Bitubo Cartridge Kit utilizes linear rate springs is not such a huge deal. Preload in fact does cover a somewhat wide weight range. And when it comes to the cartridges themselves in this kit, they are also very beefy in design and will handle damping well for a wide range of weights. If you want a system that is exactly tuned to you, then you'll be paying $2000 for a custom design instead of $525 for this Bitubo kit.

    And yes, the rear shock on the F800GS can be resprung. That's what you do with this kit:

    http://www.touratech-usa.com/shop/show.lasso?SKU=040-7401&-session=touratech:438B1F010eb9513FB7IJx22EFA1F
    #29
  10. Desert Dave

    Desert Dave Enjoying the moment

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    Really? Everytime I do that I hit the front so hard I think I'm going to bend a rim.

    How about some more info on the enduro....did I miss the ride report?
    #30
  11. bxr140

    bxr140 Flame Bait

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    Because spring rate and damping rate are dependent...and since the bitubo kit has fixed damping, there's really no point in changing the spring rate.

    That kit is going to work (...well, one hopes) for the designed rider weight (~180-200 pounds), but outside that range its probably not worth spending the dosh.

    I'm not exactly sure what you're trying to say, but:

    A. Having a suspension shop rework your forks will not cost $2000. Porbably more like $200, and they will be "exactly tuned to you", and will perform nearly as well as anything else for the vast majority of riders.

    B. Buying full cartridge internals and having them reworked will not cost $2000. Probably more like $500-600. Potentially the best option for "exactly tuned to you" if you're tiny or huge, but not worth it if you're in the bell curve of rider weights--the bitubo kit is likely the best choice.

    C. A swap to any of the various modern MX forks that will slide into the GS's triple clamps will not cost $2000. "Exactly tuned to you" plus more travel, with fairly minor cutomization. Probably $1000 when all is said and done.

    D. I don't think you actually meant it, but your statement implies that the bitubo kit is "exactly tuned to you"...which is only the case if you happen to fit the weight range to which they are tuned.
    #31
  12. M N B

    M N B would rather be riding

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    The ability to choose the spring rate in the spring. LIke you can do with any Ohlins (for $1200) or Wilbers (for $700 - $1200).


    Ding, ding! I don't see the point in getting the bitubo if it only works well for someone in the weight range the bike was designed for.

    Seems a better deal to buy proper springs and have them installed and setup by a competent shop. Unless you're 185lbs +/-
    #32
  13. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    The cartdriges in this kit at nitrogeon filled. It uses oil and the gas to dampen I guess. I did refer to my weight and ride style when ordering them dont know if that mattered though. i dont know if you guys know Drew Smith, but he is a multi time ISDE rider and mager of the team. He also has a suspension shop. He will not use progressive springs feeling they throw off the bike or make it suspend differently at different times in the stroke. I dont kmow if there is any truth to that though. But that is his opinion and he will not install them.
    I might go ahead and install these tomorrow and it seems very easy according to the instructions. Ill post all pics if I do.
    #33
  14. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    :lol3 Dave,
    Well, I guess I was expecting worse like on my Husky. Man, that was like having no front suspension ! :lol3 And I was trying to be positive and not trash the stock forks so much. But yea, they are harsh, no doubt and can be improved. I think the oil gets locked initally and cant move, causing that harshness. But Im no expert here on that.


    #34
  15. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Also Dave, it wasnt an enduro ! GOD FORBID. Those days are over for me now and the 800 wouldnt make it 3 miles into any half assed enduro ! I went to a Dual Sport / Advenutre event, riding a bit of both course. 230 miles worth over 2 days. The terrain was rocky, mountainous and muddy at times. The bike performed admirbly I must say. I was very happy with it indeed. These fork units should make me even more happy.
    #35
  16. johngil

    johngil Reseda, CA

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    I have run straight rate and progressive springs on my bikes. The valving is what is important and that it works w/ the springs. So straight rate doesn't bother me. If a spring rate can't be specified, I won't order these cartridges.
    After racing KTM's in the desert and having my suspension sprung and valved to my liking, I am picky.
    Adjustable pre load on the forks means nothing to me. Pre load won't cure a poor setup.

    I believe the next option will be w/ trailtrick and his Marzocchi internals. I'm pretty sure I'll get compression and rebound clickers. I need to give him a call.
    #36
  17. bxr140

    bxr140 Flame Bait

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    There's a lot of truth to that. Most suspension tuners will not use progressive rate springs--they're really just a holdover from old school damping rod designs, where it was difficult if not impossible to get something to damp correctly at all speeds. In the olden days it was near impossible to get the damping right, so you had to make due changing the only thing that could really be changed.

    Not using them on more modern designs (not that the GS is THAT much more modern in design :puke1 ) comes back to the fact that damping and spring rates are dependent. The range of spring rate is simply too large with progressive springs to achieve proper damping across the full range of fork speeds.
    #37
  18. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Thanks for the info bxr. Yea, Drew Smith is a prety well known guy in the enduro / ISDE curcuit. He owns Works Enduro Rider as well.
    Anyway, I dont pretend to know the first thing on the mechanics of suspension. "Just make it work for me and Ill ride the heck out of it, just dont ask me how it works or to adjust it" :lol3
    Here's what I dont get here with these and maybe someone can explain it. The cartdridges are gas filled, yet I will still pour the Silkilene 2 wt. fork oil in the tubes. Whats the oil do ? Just lubricate or are they also helping to dampen ?
    #38
  19. Desert Dave

    Desert Dave Enjoying the moment

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    O.k, I did misread your post.

    But then I did accuse DockingPilot of riding an enduro when he clearly said it was a dualsport event, only a few posts later.

    Maybe I got to much thin air in the high country yesterday :jumpSorry guys.



    So back on topic, the kit consists of linear springs which I agree are the way to go when matched with dampning valves, and if rider weight/style is taken into account (as DockingPilot noted) sounds like each kit is built to order, or at least within a range which puts these guys right back there with any quality builder. I would like to get that verified for certain, I suppose that'll be easy when I order.

    C'mon DP , install them, we're all waiting :wink:
    #39
  20. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Im installing them now and will take pics.
    As far as custom spring rates, I can tell you my answer was somewhat vague (Italian), so Im a little suspect, but I am 180lbs fully geared up, so I should be within the normal spec.
    #40