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HOW TO: 675R Ohlins fork disassembly (for oil/spring change)

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37K views 49 replies 21 participants last post by  einstein57  
#1 · (Edited)
Inspired by MGFChapin's How To thread on fork oil and seal change, I decided to try and tackle this on my 2012 675r mainly because I wanted to change to a lighter set of springs. I did not have to replace the seals.

Unfortunately, there wasn't any directly related info on this fork, surprisingly. So, through some trial and error, I managed to get through it, and honestly, it wasn't too bad.

I had posted onto MGF's original thread about some of the lessons and issues I had with the work; I hope folks w/ these same forks find it helpful... Bear in mind, this isn't really meant to be a step-by-step picture tutorial like MGF's (it was mainly just me doing the work, so I had no chance to readily snap pictures).

A quick note before getting started: I'm not particularly mechanically skilled--probably more like a shade-tree mechanic. What I do have, though, is time. Take your time, double check everything, and chances are your work will be as good as any shop. I was not under any time pressure to get the work done (i.e. not trying to get it done the night before a track day or race...).

Ok, let's do this:

FYI: On either fork leg, at the fork bottom on the inside face, there will be printed/stamped the specific model # of the fork, along w/ the manufacture date. Mine read FG9011 2011.10.07. So I know I have their FG9011 fork. Your fork may read differently, but odds are that it'll say FGXXXX on it, so these instructions should work.

TOOLS/MATERIALS NEEDED (assuming you have all the tools allowing the actual forks to be unbolted from the triple clamps):

  • FORK CAP OR TOP REMOVAL TOOL. I purchased mine from Kyle Racing--you will want his BLACK-colored 4 pronged tool. Alternatively, you could also look up "adjustable pin wrench spanner"; Dave Moss I believe uses a Facom model, which by the time you purchase the actual pins that fits, will likely cost more than the Kyle tool (but would allow you to use on other Ohlins fork top models)
  • CARTRIDGE PULL UP TOOL. Again, bought mine from Kyle Racing.
  • >1 L FORK OIL. Technically changing our the fork oil should take just <1L, but you will want to have some extra in case you mess up. Our forks specify Ohlins 1309 fork oil; I had purchased Maxima 5W fork oil prior to knowing this, but checking the oil comparison table here: https://transmoto.com.au/comparative-oil-weights-table/ shows that Ohlins 1309 has a cST of 19, whilst the Maxima 5W is 15.9. I doubt I'd be able to notice this difference, so I went ahead and used what I purchased anyhow.
  • VISE TO CLAMP FORK IN while not absolutely necessary, is very helpful.
  • MOTION PRO OIL LEVEL TOOL http://www.motionpro.com/motorcycle/partno/08-0121/
  • AN EXTRA PAIR OF HANDS. I had to have my wife help me with at least 2 steps per fork leg--compressing down the spring to allow me to undo the lock-nut that held the spring top down and vice versa. Dave Moss' video has him doing this himself, and my fingers were not strong enough to do this while simultaneously getting a 17mm wrench on the nut (perhaps also because I did not have a dedicated fork vise available).
  • YOU DO NOT NEED THE RACETECH OR SIMILAR FORK SPRING COMPRESSOR. Our Ohlins FG forks w/ the NIX30 does not have a hole/slot at the bottom of the fork leg to fit the Racetech tool, nor does it have a plastic sleeve w/ holes at the top of the spring to help w/ spring compression. I ended up using some nylon rope looped around the coils of the spring and my wife's help to compress the spring--this was the hardest part of the job, and honestly, Ohlins could have made life a helluva lot easier. Theoretically something like this http://www.traxxion.com/Fork-Spring-Compressor Kit-4017/ would've worked, but I never did try it...(you can find them cheaper on Ebay)
THE 3 MOST HELPFUL VIDEOS I CAN RECOMMEND:

  • Dave Moss' OTT video: http://www.onthethrottle.com/product/ohlins-road-track-fork-service-howto-video/ He works on a FG R&T Ohlins fork, which is basically the same as ours (our fork lowers are cast, R&Ts are billet). THIS IS THE SINGULAR MOST HELPFUL VIDEO AND WELL WORTH THE $4.99 HE CHARGES. There is nothing like seeing a high quality video, much better than still pictures.
  • SportbikeTrackGear's video on installing some Ohlins 30mm NIX cartridges into a R1 fork
PER TRIUMPH DATA SHEET FOR 675R FROM VIN 564948:
http://ascycles.com/pdf/TriumphServiceSchedules/Triumph%20Data%20Sheet%20-%20Daytona%20675%20and%20675R%20from%20VIN%20564948.pdf

  • Recommended fork oil Kayaba KHL 15-10 (SAE 5W) or Ohlins fork oil (assumed to be 1309)
  • Oil volume (dry fill) 476cc per fork leg
  • AIR GAP (fork fully compressed, spring and lower spring spacer removed) 150mm
Some pics:

Image

Quick pic of the fork partially disassembled. In order to change out the spring and oil, this is the level you will need to take it apart. You won't be messing with the NIX30 cartridge itself (which, BTW, requires a special tool to even remove--basically a long hollow socket w/ prongs at one end).

Image
Home made inverted fork holder to drain oil:smile:; notice our inner fork tube is only 1/2 nitrided--undoubtedly to save some $$

Image
 
#2 ·
The pic above shows my ghetto-fab nylon rope wrapped around the spring coils to allow us to compress the spring. You won't need to compress the spring a lot, but just enough. The Kyle cartridge pull up tool is threaded onto the cartridge also.

Again, this isn't meant to be a step-by-step tutorial--rather, if you watch Dave Moss' video, you will get a crystal clear idea of what steps you need to do.

Changing the fork oil and/or seals and springs is not rocket science, rather, it's pretty basic. My bike has ~<500mi on the odometer, nearly 98% of it track miles. The oil that I drained looked to be in fairly good shape, and I surmised I could have put this off a bit, were it not for the fact I needed to change out the springs anyhow.

All told, I probably spent $120 in the tools (not including the Racetech spring compressor that I bought but ended up not even using), another $25 on fork oil. And the experience I gained in DIY is invaluable. I'm confident that when the fork seals go bad, I'll be able to DIY without having to send it out to a reputable shop...
 
#4 ·
Excellent write-up. I'm curious, how much do you weigh and what springs did you go with? I'm 180lbs w/out gear, and wondering if I want to go one rate softer on the front springs...
 
#5 ·
I'm 135lbs without gear. Not quite sure what rate springs were OEM, in my research I got variable rates, but I believe they are 1.0 (interestingly the OEM springs had no identifiable markings). When I adjusted my preload with these, I was just barely able to get into sag range (track settings)--there would have been no further room to go.

I went with a pair of .9 springs...
 
#8 ·
Nice write up, Will order up these tools as after i send my forks out for a rebuild to include some revalving & new seals.

As mentioned stock springs are indeed .95
 
#9 · (Edited)
Glad I inspired someone enough to help ME out. Thanks for the how-to, also downloaded Dave Moss' video.

Just finished watching the video. Interesting that those Ohlins' inner tubes are fully nitrided; no cheaping out with the real deal. Also interesting that he seats the seal in the outer tube first. It does seem to make the job a bit easier but using a blowtorch on forks scares me a little. I would trust Dave with my firstborn (if my firstborn were a set of forks) though, so I'll give it a shot when I do this.

One final note - the C clip seems like a PITA. I'm going to take a measurement when I'm in there and see if I can't replace it with a stepped spring clip like you'd find on the standard Kayabas.
 
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#12 ·
Weekend oil change

Just thought I would share how nasty my oil was. I got my 2013 in June 2016 from a guy that only posed with it around town. I got it with only 1100 miles on it. I did two track days with it and then put her away to get her ready for this season. This is just how bad the oil was with only 1500 miles on her.
 

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#14 · (Edited)
I was completely blown away as to how awful the oil looked so I strained it.This is what was strained out on a coffee filter.

I tried to upload this last night but couldn't sorry.

Yes that is my unintentionally placed,
1999 AMA GRAND NATIONAL UNLIMITED SUPERBIKE CHAMPIONSHIP :grin2:

The color looks blueish green. Is that what comes from the factory? There's no way it could be the Ohlins oil. The Ohlins oil is almost like corn oil clear faint yellow tint.
 

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#26 ·
My 2014 675R has the FG R&T 43 forks. As an alternative to compressing the spring to loosen the jam nut, I modified a spare 17mm wrench (see attached photos) so that I can hold the jam nut with the upper seat (aka spring support) in place as is indicated in the service manual on page 12.19.
 

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#28 ·
You need it to pull the damper rod above the fork tube to thread the cap back on. You also need it to pump the rod up and down about a dozen times to bleed the air out. You could probably handle the job without the tool but it would take a lot longer and your fingers would be banged up/exhausted by the time you're done.
 
#29 ·
Lottery or bust?


I know most forks off the 675R have FG forks. Mine doesn't, it's FL. My Model forks:


FL9060LHA
2013.09.27


Also, while changing my fork oil/seals, I accidently turned my fork on it's side (It was already closed up), and it gurgled and could hear the fuid bounce around inside., Is it ok to use? Or should I re-service it? Everything was already buttoned up ready to be installed onto the bike. No fluid came out.
 
#30 ·
Also, while changing my fork oil/seals, I accidently turned my fork on it's side (It was already closed up), and it gurgled and could hear the fuid bounce around inside., Is it ok to use? Or should I re-service it? Everything was already buttoned up ready to be installed onto the bike. No fluid came out.
As long as you bled all of the air out before you sealed it all up, you can flip it on its side, upside down and anything in between and it'll be just fine.
 
#32 ·
You guys...I was almost too embarrassed to post this, but I need to so everyone knows. I like to think I know what I'm doing, especially with my Daytona. I'm doing my usual pre-season fork oil before our racing starts and with the extra free time, I figured I'd go into the cartridge for the first time EVER and actually clean out the shims, pistons etc. Dude. The piston wasn't even a piston anymore. It was a gloopy, filthy mass of coagulated slop, and was hardly letting any oil through the passages.

After every third race weekend, I've been opening up the forks, (usually) taking out the cartridges, hanging everything upside down for an hour or two and slapping it all back together. Not good enough. From now on, it's a full teardown or nothing. Hoping to have WAY better feel now out of my front end.

Before:
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After:
Image
 

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#33 ·
Dave moss mentions a spring and adjuster at the end of the rebound rod, but I (think) only a spring came out of mine (rebdound side). Do you recall an adjuster coming out after the rebound rod was removed? I am hoping I dont have to cut my drain pain open to find it....