R100GS Fork Inserts - INSTALLATION

Discussion in 'Airheads' started by jimbee, Dec 12, 2011.

  1. jimbee

    jimbee Airhead Intermediate

    Joined:
    Nov 11, 2008
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    334
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    I have a set of HPN inserts that I am getting ready to install. It looks fairly straight forward, but I've never opened up a set of forks, so I figure there will be questions. With other folks also getting ready to buy the Race Tech inserts, I thought it might make sense to start an install thread.

    The HPN inserts came with german instructions with pictures, and the seller was very helpful and provided some useful emails (thank you - I may bug you yet again!). I've also studied the instructions as well as a few websites (big thanks to authors!):

    http://www.rapiddog.net/BLOG/FORK%20IT.htm

    http://www.largiader.com/tech/gsforks/

    At the same time as installing the inserts, I am planning to replace all wear and tear items, and possibly powder coat the fork sliders.

    To get started, I am putting together a parts order and just want to be sure I'm getting all of bits required.

    Fork Stanchion

    [​IMG]

    Parts Order List:
    (#5) x2 – 07119963130 (GASKET RING for top of fork fill hole bolt)<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    (#3) x2 – 31421458075 (O-RING to seal Fork Top Cap)<o:p></o:p>
    (#7) x2 – 31421458077 (BUSHING on bottom of fork stanchion)<o:p></o:p>


    Fork Slider

    [​IMG]

    Parts Order List:
    (#7) x2 – 31421458065 (CUP dust cap)<o:p></o:p>

    (#6) x2 – 31421458067 (SNAP RING)<o:p></o:p>
    (#5) x2 – 31422312184 (WASHER)<o:p></o:p>
    (#4) x2 – 31421458064 (GASKET RING – aka fork seal?)<o:p></o:p>
    (#3) x2 – 31421458222 (BUSHING in top of fork slider)<o:p></o:p>
    (#15) x2 – 31421458477 (O-RING for fork oil drain hole bolt)<o:p></o:p>
    (#11) x2 – 31421458231 (GASKET RING for bolt on bottom of forks)

    Shock Absorber

    [​IMG]

    I wasn't going to order any parts for this because I was assuming that they are all coming out to be replaced by the new insert. Does this make sense?

    I'm a missing anything?

    What do you think it would cost to have the fork sliders powder coated? Do you just pull out all the seals etc and drop them off?

    I guess I need some fork oil too....

    Thanks! JB
    #1
  2. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    we require pictures of the inserts!!!!!!
    #2
  3. supershaft

    supershaft because I can

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    Chances are in my experience that your bushings need replaced. Parts # 7 and # 3 times two. Man have they recently gone up in price! It pays to change the bushed fork's oil often. Dirty oil chews up those bushings. They certainly won't come with the inserts.
    #3
  4. AliBaba

    AliBaba Been here awhile

    Joined:
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    You don't need #3 and #5




    Usually I don't remove #16 (the threads in the leg might go) and then you don't need #15.
    #5 and #6 normally last forever.

    If your indicators are mounted on the top of the forks you need another holder for the indicators, or you can modify the one you have.
    You will need a set of bar-risers!

    There are two types of spacers for the spring. I tried the short one but but changed to the long ones pretty fast, (R80 GS Kalahari with 33L tank). For me the long ones fitted perfectly!

    Long spacers (if needed), #13 (2):
    Bar risers, #9 and #10 (4,2):
    For indicators (if needed), #6 (left + right)
    http://realoem.com/bmw/showparts.do?model=0475&mospid=51694&btnr=31_0351&hg=31&fg=10
    #4
  5. jimbee

    jimbee Airhead Intermediate

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    Thank you AliBaba I will adjust my parts order accordingly. I already have bar risers installed and the inserts came with the two sets of spacers long and short.

    I have a '93 with the fairing, I remember reading here that the adjuster knobs will make contact with the bottom of the dash, and that looks probable as there isn't much clearence with the stock setup and the inserts have the extra height. Is the fix here to trim the dash? Might be time to look at losing the fairing, but I also like the stock look. I often long for a pre-fairing model, but wouldn't want to lose the tach in the dash.

    I will post pictures promise.
    #5
  6. jimbee

    jimbee Airhead Intermediate

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    Hey'o

    Well the box of parts finally arrived a couple weeks ago (stuff was backordered), and it looks like I might have a few evenings free in a row next week to finally tackle the install. I'm think I'm going to have questions and be seeking input from the collective!

    While not as exciting as all of the unholy union threads (all of which are very impressive!), I thought at least Kokopelli and his group buy buddies might find this helpful, if not a tease.

    I was half considering powder coating the fork lowers while the forks are apart, but the factory finish, while dull, is not chipping. Anyway, powder coating would likely mean I miss my install window next week and I want to get riding!

    Cheers! JB :freaky
    #6
  7. akabeton

    akabeton Adventurer

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    Photos please, or if possible I could do a drive by and take a look, help or hinder :)

    Thanks
    #7
  8. brittrunyon

    brittrunyon R 100 GS F 650 GS

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    I'm wondering about the Race Tech Gold Valve install myself?
    I've read in this forum that you only need to add the insert to one side.

    Wouldn't it be best to put an insert in both right & left fork tube?
    Making them function the same.

    For a 160 lb rider, on 50/50 riding (street/dirt roads)......
    How many turns of the tension screw on the valve?

    I'm adding springs as well, so.......
    Are the recommendations for spring upgrades by Race Tech on the money for calculating spring rate?

    :ear
    #8
  9. Airhead Wrangler

    Airhead Wrangler Long timer

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    They don't function the same to begin with. One leg only has compression damping, the other leg only has rebound. Since the gold valve acts as sort of a high speed bypass valve for the compression damping, it's not going to do you any good on the rebound side.
    #9
  10. jimbee

    jimbee Airhead Intermediate

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    Anyone have the installation instructions for the HPN Marozocci damper inserts for R100GS in English? I have them in German, and the pictures are helpful, but just thought I would ask because there are lots of "Warnings" and other "Tips" that I would be grateful to be able to read and internalize. Cheers, JB
    #10
  11. brittrunyon

    brittrunyon R 100 GS F 650 GS

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    The left/right do have different functions.....left-compression/right-rebound........

    But why not make them function the same and be structurally the same?

    Yes it requires putting a damping rod in the left (just like in the right) when adding the Gold Valve........

    This results in the ability to make the same adjustments to both forks......
    heavier oil = increases rebound
    tighten emulator = increases compression

    I'm no mechanical engineer............but this just seems to make sense.............?
    #11
  12. Airhead Wrangler

    Airhead Wrangler Long timer

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    Yes, that does make sense. The reason they were originally built this way is that the only way to adjust damping was by changing fork oil weight. By separating rebound and compression into different legs this allowed you to tune them independently of one another - one weight of oil for rebound, and a different weight for compression.
    #12
  13. brittrunyon

    brittrunyon R 100 GS F 650 GS

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    Thanks for the input.........

    What about the idea of putting a damping rod in the left and installing a Gold Valve in both (with new springs) left & right, to make them structurally the same & function the same? :ear

    Wouldn't this be the best?
    #13
  14. Airhead Wrangler

    Airhead Wrangler Long timer

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    For same or similar money you could probably just buy some nicer more modern forks, but yeah that should be possible.
    #14
  15. jimbee

    jimbee Airhead Intermediate

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    So turns out this isn't that hard. Completed most of install yesterday with a helping hand from akabeton (thank you sir), and then today greased and set steering bearings before putting it all back together. Took pictures and will post with some text, but as I was finishing up I made a VERY dumb mistake.

    I was so paranoid about stripping the fork drain bolts (5 nM) and my small torque wrench (24 nM) was right there, so I dialed in 5 NM but promptly stripped the bolt. I figured that 5 nM was 20% of torque wrench max so that it would probably be acccurate.....

    Anyways, I'm pissed because everything else went so smoothly. Stupid stupic stupid me.

    So, what is the fix?

    The drain bolt is so short that I only pulled out about half the threads. Should I go with a longer bolt and hope that it doesn't interfere with the internals. Presumably the bottom cap of the inserts is all that a longer bolt would potentially touch.

    I happen to have a 6mm x 1 timesert kit, but it looks like the countersink bit would not fit into the hole becuase there is a metal collar cast into the fork lower around the hole.

    Helicoil?

    Anyone else done this before?

    Help and experience gratiously appreciated!

    JB
    #15
  16. AliBaba

    AliBaba Been here awhile

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    Hmm....
    If there is enough threads use locktite and a longer bolt and never unscrew it again.
    #16
  17. brittrunyon

    brittrunyon R 100 GS F 650 GS

    Joined:
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    Oddometer:
    645
    Location:
    The High Desert of New Mexico
    A few years ago I found the drain plug on the right fork was stripped and was able to "carefully" drill out and insert a Helicoil.
    I've drained them a couple of times & the insert continues to work fine.:thumb

    The forks are off the bike, in pieces and being rebuilt now.
    I putting in Race Tech springs & Gold Valve emulators.

    I'll find out soon if the Helicoil continues to be secure.
    #17
  18. jimbee

    jimbee Airhead Intermediate

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    AliBaba - your words were ringing in my head.

    If you don't remove the drain bolt, I assume you drain from bottom bolt. Works fine?


    Good to know that this is a viable option thanks, and hope your install goes smoothly.
    #18
  19. AliBaba

    AliBaba Been here awhile

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    Normally I remove the top of the fork and the spring. I always clean the internals when I change the oil anyway.
    #19
  20. JZed

    JZed Have GS will travel.

    Joined:
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    Jorunny,
    There is a pair of BMW Sport Springs listed on Fleabay (Item 110779799609). Bought and installed a pair a few weeks ago. Stiffened up the front end a bit and helped the bike when loaded 2 up for camping. Think we bump the gross weight limits. I am going to try playing with the folk oil viscosities next. The UK GS list has some interesting reading on the subject of fork oil cocktails to get the suitable ratios.

    Nice Videos on Zed BTW

    Ride Safe

    JZed
    '86 R80
    '92 R100GS
    '06 KLR650
    #20