F800gs - Almost perfect except for poor suspension.

Discussion in 'Parallel Universe' started by mac444, Oct 22, 2008.

  1. Lucky Jack

    Lucky Jack Amateur Barbarian

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    thanks that was a very helpful reply
  2. The Griz

    The Griz North Forest Rider

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    I'm assuming, yes, this would be antifreeze. Due to the fact that the coolant reservoir and coolant lines to and from the motor and radiator are on the right side. As well as the fact that the stock coolant BMW puts in is blue in color! Check the two fat hoses that come from the radiator and connect to the engine on the right side. They may have worked loose. There's not much else that would leak. Even upside down. The forks and rear shock are sealed. The gas tank is sealed. The battery is sealed AGM Maintenance-free. Engine oil is sealed. Has to be a coolant leak.
  3. Lucky Jack

    Lucky Jack Amateur Barbarian

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    cool, thanks, Griz
  4. sgopher185

    sgopher185 Been here awhile

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    This seems to be what I was thinking of doing to my f800gs when I have the funds.

    Just to clarify do you mean each fork has rebound and compression adjustment or is one fork set up for rebound and one for compression?
    If these are set up as the latter (one for rebound, one for compression), is it possible to set up both for rebound and compression like the te610 marzocchi forks (06 and 07 I think)?

    Definitely looking forward to the pictures.
  5. lawe

    lawe lawe

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    Has anyone tried the emulators from Race Tech? They have an emulator to put into damper rod forks which shall make it behave like a catridge fork. The have emulators for the F650 single but not for the F8 accoring to the web site (i have emailed them though)

    But do these emulators really work?

    EDIT: Here's a good link about the emulators: http://www.sportrider.com/tech/146_9502_tech/index.html

    /Lars
  6. huckleberry

    huckleberry BACK ROAD BOMBER

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    they haven't made them yet they need a bike so they can make them soooooowe need someone to drop off their 650 and someone to drop off their 800 so they can make them!!!!!
  7. lawe

    lawe lawe

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    Anyone with an F8 in the neighbourhood of Race Tech?

    I'm a bit to far away i'm afraid...
  8. itsatdm

    itsatdm Long timer

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    I have been preaching to reduce oil viscosity as a cure for the BMW fork issues on the 800, hard to admit, but I was wrong.
    After attempting to get some information about these forks from BMW, Marzocchi and Rev Tech without much success I found thes people: http://www.aftershocks-suspension.com/pages/contact.htm
    Not only have they taken these forks apart, they actually fix them. No I have not utilyzed their services yet, but they did pass on some valuable information.
    As Trailtrick discovered, these are indeed damping rod forks. They are set up for 160# riders and work fairly well for those riders, if the rider weighs more than 180# you start experiencing the problems noted on this thread.
    Contrary to what I thought, the holes in the damper unit are not too small they are too big and located in the wrong place, right at the bottom of the damping unit. What we are experiencing is a hydraulic spike, where too much oil is coming into the unit with no place to go. Their cure is to reduce the size of these holes and place others further up the unit, which again sounds like what Trailtrick is doing. In my case they suggested heavier oil to slow the flow into the unit and elongate the spike, thus feel smoother.
    So I tried the 10 wt. oil that Hyperpro sent along with my springs and guess what, it works.
    Further tidbits, included that the first step in getting a better ride out of the 800 is to deal with the rear shock. I don't understand all of it, but Bmw built these bikes to mimic the ride of the larger GS and they seem to think that improving the rear is key.
    Apparently I did not do everything wrong, these bikes do not like preload and are very sensitive to using it to correct sag issues. I managed to do that, with the changing out of both springs and the use of coil spacers on the front. That is probably where my improvement came from.
    They also do not seem to think that cartridge emulators will solve the problem alone and recommend modifying the the damping tubes with or without them although they will give you more flexability.
    My current set up is Hyperpro front and rear, coil spacers used on the front, 10 weight oil, no preload on the rear, max rebound. The brand of spring is not that important, the key is to arrive at the proper sag.


    Its the internet read then verify
  9. Bayner

    Bayner Long timer

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    Thanks for the update Itsatdm. I haven't ridden mine offroad yet as the snowline is still at the valley bottom, but I suspect I will want to improve the suspension preformance when I do as I'm coming from a thumper background. Your info and experiences are going to prove valuable no doubt.

    :freaky
  10. Eurastus

    Eurastus Hej på dej!!

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    OK, I understand no preload. That's simple enough. But do you mean that you have the damping screw tightened all the way clockwise, giving maximum damping (hard), or loosened all the way counterclockwise giving maximum rebound (soft)?

    The manual seems to be contradictory.

    On page 52 and 53 it states that the recommended settings for a 187 lbs rider with gear (pretty much my weight) is for no preload; it states to turn the preload counterclockwise all the way. Damping is recommended to be set almost at maximum; it states to turn the damping all the way in clockwise to make it hard as possible, then back off 1 1/2 "clicks" (I feel no clicks in the damping screw, by the way, though I do feel "clicks" when I loosen the preload adjustment). Perhaps they mean 1 1/2 turns?

    Yet another statement on page 52 is that "...a reduction in spring preload requires softer damping". This seems to be the opposite of the recommended settings.

    Am I not understanding or is there indeed a contradiction here?

    As you suggested, I am reading...then verifying.
  11. itsatdm

    itsatdm Long timer

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    Clockwise= more damping. You should only use enough to get the desired effect. Generally, the stiffer the spring, the more rebound damping is required . I am near max on mine (1/2turn out from full hard) because of the stiff spring I am running on the rear, the stocker should not require as much.
    Mine doesn't click either. The great unknown is just how effective the damper unit is in the first place, though I could certainly feel the difference.
  12. Eurastus

    Eurastus Hej på dej!!

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    Do you know if the damping on the stock setup is compression, rebound, or both?

    What do you judge is "the desired effect"?
  13. tmex

    tmex Long timer

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    I've used Aftershocks for some KTM suspension work when they were located in Palo Alto. Phil Douglas is a good guy and knows what he is doing, but like all suspension shops you never know exactly when you will get something back and what exactly you will get back. Phil's shop does not exactly inspire confidence - looks like an explosion in a fork factory. I had good luck with them.

    Javier has a great reputation as well, and when I get past this lazy period I am in I am going to let him breathe on my HP2 forks. The F800GS seems to just keep getting better and better the more I ride it. I am either getting used to it or it really is breaking in - maybe a combination of effects at work here.
  14. The Griz

    The Griz North Forest Rider

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    Go to hear, tmex!
  15. itsatdm

    itsatdm Long timer

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    It controls rebound only. I interpret it to mean, hard enough the rear doesn't spring up too quickly or bounce more than once, yet hard enough that it doesn't rebound so slowly that the shock packs. If it is any help, I tried all kinds of setting with the stock spring at 1&1/2 turns out.
  16. itsatdm

    itsatdm Long timer

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    I have only spoken to them on the phone. What impressed me was that they knew exactly what I was experiencing even before I told them, they were very open with their solutions and discussed with me a lot of cause and effect things that mirrored my own experiences.
    I would rather let them speak for themselves, but a couple of things they seemed adamant about. If you are unhappy with the suspension look at the rear shock first. They seem to like the lightest spring available that gives proper sag without a lot of preload or rebound. Weight the front.
    In my attempt at a cheap solution, I ended up at the same place via a different route. Instead of an aftermarket rear shock I reprung the stock one. It requires no preload to achieve proper sag but does rquire a lot of rebound control. That may be an issue with the capability of the BMW shock. On the front, I previously mentioned that the Hyper pro variable rate spring did not seem to be substancialy larger in diamenter than stock. I achieved proper sag by using a coil segment to replace the spacer. The result is a variable rate spring, very compliant initially than heavier as it compresses. The last, was a heavier weight oil to slow flow through the damper.
    The current set up is a dramatic improvement over stock, in the first 700 miles I rode it. Maybe further breakin mile would have resulted in a lessor amount of improvement but I will never know. At speeds over 35mph I don't even feel things that actually hurt my wrist previously.
    I doubt my improvements will match what is available in the aftermarket, but if this bike was delivered with the ride it currently has I never would have posted on this thread complaining about it.
  17. huckleberry

    huckleberry BACK ROAD BOMBER

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    ok so has anyone done anything to the 650 forks? i notice mine drops 2 inches under its own weight, is this bmw's way to adj height or are the springs just that soft?:jjen
  18. JohanRens

    JohanRens n00b

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    Similar experience, changed to 800GS after 950S has been stolen. Had KTM 640 Adv before that. Done 300 km (bike total 3000 km = 5 months old) on gravel road (not MX). Gravel road conditon fair but not good, maintained speeds less than 120 km/h. Indeed, this machine is "NOT ready to race" . Front suspension collapsed- hydraulic response is totally gone- although oil is not leaking out. BMW dealer could do nothing more than agree that one will have to stick to the tar until aftermarket solution becomes available. What a disappointment! Stick to KTM, from the floor it is ready to race. Good motor though.
  19. tmex

    tmex Long timer

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    Johan, my first dirt ride on the F800GS created a similar impression as yours. However, the following made a very big difference.

    1> Mount knobbies and run 22-25 PSI front and rear

    2> Increase rear pre-load to near maximum

    3> Raise forks in triple clamps about 1/4" or so

    4> Unless you are less than 5'9" bar risers are essential (25mm)

    5> Flog the bike hard for 2000 miles or so - it does break in.

    I would not categorize my F800GS as "ready to race", but I would not race a 990, 950, or 690/640 KTM either. My racing is limited to 450 class four strokes or 250/300cc two strokes. For what I would call adventure riding, the F800GS with the above changes is very very good.
  20. Harry Swan

    Harry Swan One more time

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    I'll add better springs to that list (depending on your weight.)

    I rode my first ride on an Ohlins front fork springs equipped f800GS yesterday and I found it a much better ride than the OEM setup. Much better for me at 220 lb. plus for feedback and a whole lot less pounding than I got from my f8gs today on the same rough road. I'll be placing my order. FWIW, I always find for my weight that I need to beef up the front end, but $130 is easier to take than replacing a shock on my R11's....