RMZ forks on a F800GS - front end swaps for dummies

Discussion in 'Parallel Universe' started by Snowy, Mar 31, 2013.

  1. Snowy

    Snowy Long timer

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    OK trend setters, so you've noticed your F800GS is lacking in the front springy thing department. When you line up a rocky bit of trail, you get a lot of "krunch", and "KER thunk" where it should have been "oh yeah...that's it baby...do it again"?

    Well have I got the solution for you!

    I saw an ad for Emig Racing custom billet alloy triples for the F800GS. A friend (God bless his cotton socks) knew I was tearing what little hair I had left clean out of my head in despair over the woefully inadequate suspension on my F80. He had many, many smart assed comments, but then simply suggested I read the Emig website again as they advertise that they'll bore triples to suit what ever fork you want.

    What ever fork you want.

    OMG, OMG, OMG.....so excited!!

    So as fast as my laptop would function, I get onto their website and start the email inquiries. They were very helpful, and simply requested that I confirm the diameter of the forks at top and bottom triple clamps.

    I ran to the garage so fast I spilt beer every where, measured the forks and sent the numbers, cursing the slow ADSL2+ connection speed.

    After swapping financial details and confirming my order I had the parts inbound.

    Bastard customs intercepted them and held them to extortionate ransom claiming I had exceeded the import duty quota, so after sending an email cursing them and their offspring, and demanding my parts before I sanctioned a pre-emptive strike, I finally got the paperwork to fill out.

    My impatience had approached total despair at this stage. I was ready to go Black Ops on the their asses.

    Then the parts showed up.

    OMG, OMG, OMG, I think I ran in small circles while trying to figure out what I should do next.

    Within about 32.3 seconds of accepting the parcel I was in the garage tearing it to pieces like a 10 year old attacking the wrapping paper on Christmas morning.

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    I just happened to already have a set of RMZ forks that had been set up for getting air on a DR 650. Special attention paid to the high speed compression. I could jump that combo just like I was riding a 250. Good times.

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    Close up showing the steering damper. One of the best additions you can make. This one kept leaking like a sieve. Turned out to be a split o-ring on one of the drain screws, and the o-ring on the shaft with the adjustable knob on top. I got it to stop leaking, but after about 10,000kms it started again. I'll strip it down again and try for a more permanent solution.

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    RMZ forks in triples with the original F800 fork laid next to them.

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    Within 20 mins of receiving the triples, the bike looked like this, and that's where the trouble started.

    First of all the steering head bearings where shot. Off to the bearing shop the next morning. I was fuming.

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    After the bearing shop, I slapped it together for a quick fit up. Lots of little niggles.

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    First I had to use the die grinder bit on the dremel and add a curve to the inside edge of the steering stop so it would clear the steering head tube.

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    Then the steering stops needed trimming to allow full lock so the steering lock would engage.

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    Look....adjustments....ooooohhhh

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    Which brings me back to all fitted together ready for test ride without ABS.

    Impressed by the test ride I set about manufacturing an ABS bracket from stuff laying around on my workbench.

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    I used the original front wheel minus one disc, and made a caliper spacer bracket. I used to standard front axle, trimming 5mm off the threaded end, and using an internal sleeve in the left hand axle clamp, as the BMW axle is the same dimensions as a 06 RMZ axle, but the 07 RMZ forks have a slightly larger axle. Something I learned the hard way a couple of years back.

    So I played with the set up for a while and eventually fitted a DR front master cylinder.

    Here's a shot pre DR master:

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    I have since changed the brake lines to run like an RMZ, buying new braided stainless steel lines, slightly longer so I could route them right.

    I'll take some close up snaps and upload them. I've been so busy riding it I haven't really done pics or anything else.

    Some ride impressions later.
    #1
  2. ebrabaek

    ebrabaek Long timer

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    Great write up.... The more I think of it, I am going to learn towards the single rotor setup. I have banged the wide load dual on too many rocks, and I need to gain about 1/2-3/4 inch of height in the front to accommodate the 18 in the rear. Very nice.....
    #2
  3. Snowy

    Snowy Long timer

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    Taking a break


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    #3
  4. Snowy

    Snowy Long timer

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    [​IMG]

    Brake line routing.

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    Caliper spacer bracket

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    DR master cylinder. Took some serious stuffing around to mount the switch for the brake lights.

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    Again with the Brembo

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    My choice of rubber for the 2 up trail riding.
    #4
  5. slowpoke

    slowpoke Been here awhile

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    Looks great!
    #5
  6. Snowy

    Snowy Long timer

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    [​IMG]

    After a fun long weekend, I mowed the yard, washed the bike, drank some beer and fell asleep on grand daughters trampoline.

    I awoke to her knocking on my forehead and asking if anyone was home.

    Heaven.
    #6
  7. Grits&Gravy

    Grits&Gravy Been here awhile

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    Snowy, thanks for sharing. I've been considering going to a high fender and a single rotor on the front, and I also have ABS. Recently I read about someone saying it would cause the brakes to do something blah, blah, blah, and now I can't find where I read that. Anyhow, I was curious to know if you noticed any difference in the braking characteristics with one rotor vs two and what your opinion is of this setup. Thanks

    BTW, awesome looking bike and really nice new hardware with that triple.
    #7
  8. dendrophobe

    dendrophobe Motorbike Junky

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    Nice job! I agree with you, a full front end swap really transforms the bike.

    As far as the single rotor... In my case, I feel that two is overkill; I'd never run a single disc on my Ducatis, but this is a different beast! As long as you change the master, you're ok; if you don't, things are a bit squidgy (I'm currently running, and hating, the stock master). But that's mainly lever feel. Braking is adequate as long as you realize it's not a race bike. YMMV.
    #8
  9. bastimentos

    bastimentos Been here awhile

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    I love that people rate these bikes so highly that they would rather spend a ton on expensive mods than go and buy a separate bike to compliment the F800GS. "Piss off, I will do everything I want to do on ONE motorcycle" :rofl

    I share the same irrational love of modifying the one bike to rule them all mentality.

    What is the weight of a single rotor that some off y'all are deleting, are you noticing a significant benefit? Does it not potentially void your insurance?
    #9
  10. Hamish71

    Hamish71 Been here awhile

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    Nice work Snowy....
    I went the KTM front end http://www.advrider.com/forums/showthread.php?t=867915

    A lot of our solutions are similar. I will try and post some better picks soon.

    Spent the weekend smashing around the high country in Vic....now I need to fix that rear shock!

    Look forward to catching up with you sometime soon.
    #10
  11. Snowy

    Snowy Long timer

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    Weight wasn't the issue with the rotor, just that most proper dirt bike front ends only have one caliper bracket.

    Insurance is a grey area. If i have an accident that's my fault, and they establish that the brake mods contributed....better get yourself a lawyer son, better get a real good one.

    If I bin it off road it will be me paying to fix it anyway. I've read the fine print on my insurances, and anonymously asked questions, the conclusion being that I'm paying for third party, property and theft.

    I figure it works fine, the F650 came out with only one disc, same weight, same capacity....if it ever went legal I have a case.

    Long term I want to pick up another set of RMZ forks and get the F800 axle clamps machined to fit. Then run both discs.

    Testing of the ABS was fun. For those of you with ABS, the ultimate leap of faith is bang down a gravel road at 100kph, and slam the front brake as hard as you can and hold it on and let the ABS stop you. Then try to stop front only without ABS.

    After doing it DOZENS of times I can safely say I think some of the anti ABS videos are pure shit. The front end being less prone to diving, and the forks keeping the wheel firmly on the ground also help with the rear ABS not activating quite as easily.

    All told, the fork swap has improved this bike so much I didn't bother chasing a test ride on a KTM990. I cancelled the BMW R1200GS that was 3 months out on order, and I spend all my spare time riding this. I have 2 extremely modified DRs that I now want to sell because I just don't ride them.

    Here's the message for BMW, this bike of yours is now FUN to take off road. Even into extreme "it wasn't built to do this" off road. It's a handful fully loaded, it'll test your skill and concentration in the real hard stuff....but it's FUN 100% of the time. It will surprise and amaze at just how much it will do and how far it will go.

    And the slack jawed looks from people when they come across you in the middle of some rutted rocky spurline track, wife on the back and camping gear strapped on, are well worth the effort that went into it.
    #11
  12. runnin4melife

    runnin4melife Been here awhile

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    "No shit when I was back at Bragg!!!"
    Two questions, how much were the triples, and where can I get some 06 RMZ forks? I would do this in a heart beat! :evil

    Oh yeah I have a Scotts damper, did you have to do anything weird to fit your damper?
    #12
  13. Snowy

    Snowy Long timer

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    The triples with shaft and steering Damper were about $1100 US.

    I used 07 RMZ dual chamber forks, slightly different diameters to the 06 single chamber. I got mine new off eBay from a US Supercross team for $400 US.

    Parts New and Used have been great for a few purchases now, they do RMZ 250 forks usually for about $280, and 450 forks for around $320. Same fork, depends on who had them as to spring rates.

    I've also used "Keepitroosting" with great success. Prompt and efficient service every time. I've found since the GFC that online shopping from the US has been excellent with everyone working very hard to delivery great service. A credit to good people in hard times.
    #13
  14. Snowy

    Snowy Long timer

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    Oh, the damper wasn't too bad, but the post that it anchors to was a real bitch. Ended up shortening it, and the pin that fits inside.
    #14