changing fork oil
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Warchild
Benevolent Dictator
Do be aware, gentlemen: that particular FJRTech article was authored by Mike Carpenter (mcarp) over two years ago, so what may be known now may not have been known back then.
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HaulinAshe
Well-known member
I just did my forks for the first time last night. Had the 05 since May, put 20,000 miles on her since then. My (original) fork oil was good, but highly contaminated.
Don't confuse fork servicing recommendations for other riding environments with touring requirements. On your "typical" FJR that's ridden on public highways, contamination would be the number one reason to change fork oil. Even if nothing inside the fork ever wears, forks are constantly exchanging air as they work up/down and heat/cool from riding. Everytime you wash the bike, ride in rain, ride a sandy or dusty area, contaminants manage to make it past the seals and into the fork oil. The regularity with which you change fork oil, probably affects seal life and fork tube surface condition more than fork performance.
In motocross we change fork oil whenever we change underwear, perhaps MORE often. But motocross places high demand on the oil, has huge levels of contamination per hour of operation, and is basically the worst case scenario for fork manufacturers. Me and my FJR ain't doin' no woops anytime soon!
My suggestion is that the most important fork oil service to perform is the first one, whenever you decide that should be. Based on what I found last night, I would say one year or 20,000 miles, whichever comes first. Then change it every year or 20k thereafter.
As to what oil to use... the only commonly available grading system for comparison between manufacturers is weight. Go buy yourself three quarts/liters of a good synthetic 10w fork oil. Maxima, BelRay, Amsoil whatever. Use one quart to flush like hell. You'll need the other two to fill the forks.
Switching to 5w in the same brand/type oil will produce slightly softer suspension (for the same clicker settings) but will primarily give a quicker response to massive suspension movements. Are you planning on jumping some doubles or perhaps clearing the fountain at Caesar's palace?
5w would be my recommendation for someone who primarily runs on track conditions and consistently in triple digit speeds. Or, someone who lives in a very cold climate and prefers not having to "warm up" their suspension. But if you are a hefty person in a cold climate, then you probably want to stick to 10w because the suspension will be too soft for your taste. Get the picture? 5w, 10w, 15w all depends on your environment, rider weight, riding style, road conditions etc. The 10w recommendation is a good middle-ground that works well for most people and most conditions.
Here's my recommendation... buy good synthetic fork oil and change the ****! You are probably already past due for the service.
My 05 called for something like 22.3 ounces per tube. The critical setting is the oil height not the oil volume. Forget the volume. MEASURE THE OIL HEIGHT AND MATCH BOTH FORKS. I'll edit this post and add a pic of my inexpensive fork oil setter upper. My 05 called for 100mm below the tube.
Before you jump into changing fork oil viscosity, invest in some study of how the bike behaves. Grab a buddy and get some video of your bike to study. Know what you want and what you expect before you start making drastic changes to the bike.
My $2.00 :lol:
Don't confuse fork servicing recommendations for other riding environments with touring requirements. On your "typical" FJR that's ridden on public highways, contamination would be the number one reason to change fork oil. Even if nothing inside the fork ever wears, forks are constantly exchanging air as they work up/down and heat/cool from riding. Everytime you wash the bike, ride in rain, ride a sandy or dusty area, contaminants manage to make it past the seals and into the fork oil. The regularity with which you change fork oil, probably affects seal life and fork tube surface condition more than fork performance.
In motocross we change fork oil whenever we change underwear, perhaps MORE often. But motocross places high demand on the oil, has huge levels of contamination per hour of operation, and is basically the worst case scenario for fork manufacturers. Me and my FJR ain't doin' no woops anytime soon!
My suggestion is that the most important fork oil service to perform is the first one, whenever you decide that should be. Based on what I found last night, I would say one year or 20,000 miles, whichever comes first. Then change it every year or 20k thereafter.
As to what oil to use... the only commonly available grading system for comparison between manufacturers is weight. Go buy yourself three quarts/liters of a good synthetic 10w fork oil. Maxima, BelRay, Amsoil whatever. Use one quart to flush like hell. You'll need the other two to fill the forks.
Switching to 5w in the same brand/type oil will produce slightly softer suspension (for the same clicker settings) but will primarily give a quicker response to massive suspension movements. Are you planning on jumping some doubles or perhaps clearing the fountain at Caesar's palace?
5w would be my recommendation for someone who primarily runs on track conditions and consistently in triple digit speeds. Or, someone who lives in a very cold climate and prefers not having to "warm up" their suspension. But if you are a hefty person in a cold climate, then you probably want to stick to 10w because the suspension will be too soft for your taste. Get the picture? 5w, 10w, 15w all depends on your environment, rider weight, riding style, road conditions etc. The 10w recommendation is a good middle-ground that works well for most people and most conditions.
Here's my recommendation... buy good synthetic fork oil and change the ****! You are probably already past due for the service.
My 05 called for something like 22.3 ounces per tube. The critical setting is the oil height not the oil volume. Forget the volume. MEASURE THE OIL HEIGHT AND MATCH BOTH FORKS. I'll edit this post and add a pic of my inexpensive fork oil setter upper. My 05 called for 100mm below the tube.
Before you jump into changing fork oil viscosity, invest in some study of how the bike behaves. Grab a buddy and get some video of your bike to study. Know what you want and what you expect before you start making drastic changes to the bike.
My $2.00 :lol:
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dcarver
Well-known member
I use diesel fuel to clean the innards. Works great, relatively cheap and no problems yet with rubber swelling etc.
Hotboot
Well-known member
Warchilds photo gives me a case of smell-o-vision, smell that stuff after 10K and tell me it's not bad for internals. The silver color just looks like worn parts to me. Surprised Lee has not chimed in here yet, all factory forks are less than perfect and some wear more than others. I'm sure there are many 60,000 mile bikes out there with original fork oil too.
yamaholic
Well-known member
Correctomundo! I had no idea (I'm the old mcarp) whatsoever that viscosity ratings were not based on simple W ratings. I personally am keeping it simple by using the same brand and viscosity (Silkolene RSF 10W) and adjust clickers and oil height as experimentation factors.
Quik...I suggest you experiment with oil height (higher), preload (turn it in, a little does a lot) and clickers (go stiffer) and setting sag again at both ends before changing the oil out to a different brand. Another thing to consider is wheel alignment. I've messed this up before on another bike and similar results as you've mentioned. Keep in mind your old oil was probably getting thicker than stock due to particle buildup. Have you been slowly softening things up since you got your '03?
quicksilver
So.., how fast does that thing go?
Hi Mike :blum: :hi:
When I thow in the new springs, I guess the old baseline will go out the window.
I hope just a stiffer spring rate brings nirvana.
Plan B, will be to try higher oil level.
I like the idea if sticking with same oil and adjusting oil level.
Sounds wise and takes all the high tech bla,bla, out of the picture.
Haven't adjusted anything softer. maybe never.
All clicks are almost completely "in" these days.
(which contributed to me considering heavier oil)
Front wheel alignment seems fairly staight forward.
As long as I tighten the axle before the triple clamp and then superbrace last.
Good one to watch for though.
When I thow in the new springs, I guess the old baseline will go out the window.
I hope just a stiffer spring rate brings nirvana.
Plan B, will be to try higher oil level.
I like the idea if sticking with same oil and adjusting oil level.
Sounds wise and takes all the high tech bla,bla, out of the picture.
Haven't adjusted anything softer. maybe never.
All clicks are almost completely "in" these days.
(which contributed to me considering heavier oil)
Front wheel alignment seems fairly staight forward.
As long as I tighten the axle before the triple clamp and then superbrace last.
Good one to watch for though.
HaulinAshe
Well-known member
Just a bit of a warning...
Adjusting the oil level primarily effects the behavior at, or near the end of travel (absolute compression). If you are looking for significant changes throughout the range, then a viscosity change may be in order.
IMHO If you already have the clickers shut all the way down, then you need different springs and a fresh start.
Adjusting the oil level primarily effects the behavior at, or near the end of travel (absolute compression). If you are looking for significant changes throughout the range, then a viscosity change may be in order.
IMHO If you already have the clickers shut all the way down, then you need different springs and a fresh start.
yamaholic
Well-known member
Yo B-Well, stiffer springs will change the handling a lot. The key, however is balance.
Do you also have a wilburs shock or are you still stock? Stiffening the front will tend to squat the rear more, shifting weight back, and handling prowess suffers. If you haven't upgraded the shock, all I can say is just do it! And the fork rebuild/spring GB is you can swing it.
Maybe the front tire is not tracking due to fall temps; tire is not warm? I've noticed slippage when squidly on the front brakes on cold Avons, or if pressure is too high.
BTW, you up for any rides or tech clinics this year?
quicksilver
So.., how fast does that thing go?
A fresh almost new OE '05 shock is on the way and will get shimed 3/16. (thanks to DRFJR)
That's the best the coin purse allows this year.
I am planning my '07 out of state rides at the moment.
The Gap in Spring (maybe early June with LGizmo)
The EOM (see youe there)
Probably Kentucky or Ohio overnighters in the summer.
There will definitely be an Spring group ride in Hoosier National forest.
After 4 years there are finally enough IN riders to represent.
Found a cool new road yesterday.
With the cool temps we went 25 minutes without catching up to a single car.
I am up for a maintenance thing, but roads suck around my house.
Maybe we can get someone in SW Ohio to step up as host?
That's the best the coin purse allows this year.
I am planning my '07 out of state rides at the moment.
The Gap in Spring (maybe early June with LGizmo)
The EOM (see youe there)
Probably Kentucky or Ohio overnighters in the summer.
There will definitely be an Spring group ride in Hoosier National forest.
After 4 years there are finally enough IN riders to represent.
Found a cool new road yesterday.
With the cool temps we went 25 minutes without catching up to a single car.
I am up for a maintenance thing, but roads suck around my house.
Maybe we can get someone in SW Ohio to step up as host?
yamaholic
Well-known member
Gotcha. The new shock will be a godsend! All bets are off right now with worn out suspension.A fresh almost new OE '05 shock is on the way and will get shimed 3/16. (thanks to DRFJR)That's the best the coin purse allows this year.
I am planning my '07 out of state rides at the moment.
The Gap in Spring (maybe early June with LGizmo)
The EOM (see youe there)
Probably Kentucky or Ohio overnighters in the summer.
There will definitely be an Spring group ride in Hoosier National forest.
After 4 years there are finally enough IN riders to represent.
Found a cool new road yesterday.
With the cool temps we went 25 minutes without catching up to a single car.
I am up for a maintenance thing, but roads suck around my house.
Maybe we can get someone in SW Ohio to step up as host?
As for rides...I kinda doubt anyone will step up in Ohio. No one has yet, I'm basically too busy to even conceive of doing it for the 6th time. Heidi is ringleading the EOM this year. There is an Ontario ride in the planning stages.
make sure the S. Indy ride is publicized. I'll be there if I can swing it!
No where in the service manual (put forks in and tighten pinch bolts) or the online directions for reinstalling the forks does it talk about alignment. Are there guides in the triple trees that the forks will only go in one way?
evil_henchman
Well-known member
The wheel is your guide. Pop your forks up into the tree and tighten the pinch bolts. Note that you can spin the lowers round and round so obviously it doesnt matter how they go into the tree. Once you put the axle through the wheel, it's aligned. Assuming you didn't get the left and right mixed up B)No where in the service manual (put forks in and tighten pinch bolts) or the online directions for reinstalling the forks does it talk about alignment. Are there guides in the triple trees that the forks will only go in one way?
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quicksilver
So.., how fast does that thing go?
Do final torque on triple clamp after the wheel is mounted. The front axle gets it aligned for you.No where in the service manual (put forks in and tighten pinch bolts) or the online directions for reinstalling the forks does it talk about alignment. Are there guides in the triple trees that the forks will only go in one way?
Torque axle pinch clamp, then go lock down the bolt up top.
edit- Evil types quicker than me.
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Thanks. I just had a Mencia Dee Dee Dee moment.The wheel is your guide. Pop your forks up into the tree and tighten the pinch bolts. Note that you can spin the lowers round and round so obviously it doesnt matter how they go into the tree. Once you put the axle through the wheel, it's aligned. Assuming you didn't get the left and right mixed up B)No where in the service manual (put forks in and tighten pinch bolts) or the online directions for reinstalling the forks does it talk about alignment. Are there guides in the triple trees that the forks will only go in one way?
https://video.google.com/videoplay?docid=5258682047377060663
sleddoc
Well-known member
radman
R.I.P. Our Motorcycling Friend
As stated before, height is a better measurement than volume. After adding oil up to the 100 mm mark, pump the fork tube 10 times to purge air and completely fill the various valves and passages (spring removed of course), then remeasure and add to the mark. Only then can one be assured he's done all he can to have the correct fill volume IMHO.
06 shop manual calls for 23.53 oz or 696 cc's Height is the way to go as Radman says and 06 is 92mm.
Cal24Master
Well-known member
Cal24Master
Well-known member
Changing the oil level is the wrong thing to do. Raising it will simply but the burden of supporting the weight of the front end on your fork seals. If you over fill them, it will blow out your fork seals. If you underfill them, the oil will foam from sucking air and you will lose dampning force. The correct way to adjust it is to change the viscosity of the oil. If the manufactures had ever meant to have oil level as a adjustment, they would have listed the level as a variance, ie. 100-150 cm etc.
Tom
