Fork Oil questions?!


Superfly

New Member
I've been planning on changing out the front fork oil as the rebound seems to be way to light on damping. I checked the technical manual and it states that the OEM oil for the fork is Yamaha 01 suspension oil. After reading all this:

what weight is yamaha 01 suspension oil? : Yamaha R6 : R6 Forum

And then seeing this:

Yamaha Motor Corporation, USA - Lubricants & Grease 01 Suspension Oil

I'm pretty sure that our bikes come with 0wt oil stock. I'm going to increase that up to 5wt as a starting point...

Now here is my big question: Looking at the parts schematic can I just suspend the bike in the air and then drain the oil from the fork with a drain bolt at the bottom of each fork leg? And then refill from the top hex nut cap? Am I looking at this correctly? I'm guessing that I have to remove the axle first to get at the drain bolts...I plan to do one at a time...drain the 0wt and then refill with 16oz or 475mL of 5wt...

Anyone got advise??? Thanks :)
 

Roaddawg

New Member
I've been curious of the same thing. A buddy of mine use to own a motorcycle shop and he told me to change the fork oil out with a heavier weight as well. Said the stock oil is crap. He said there should be a drain in the bottom of the forks like you described. Anyone done this yet?
 

Superfly

New Member
I'm hoping its as easy as this...vintage 70s bike...by the sound of the accent I'm thinking east coast Canada...might even be the rock :D

[ame=http://www.youtube.com/watch?v=38yXx64liCM]YouTube - Motorcycle Fork Oil Change Part 1[/ame]

found this weight table...not sure what it all means but it kinda looks like 5wt will be close...might be worth it for a tad more 7.5 or 10wt...guess all the manufacturers are different too...

Fork oil weights
 

owldaddy

New Member
The bolts on the bottom of the legs are not drain bolts, they secure the damper rod. That being said, in the past forks did have drain bolts on the side of the legs, why they don't any more makes me crazy. How much can it cost to drill a hole, tap it, and install a small bolt? Can the damper rod bolts be removed and used to drain the fork leg? I don't know, I doubt the oil will get past the damper rod. I can tell you it only takes 20 minutes to remove the forks and dump them. That is the suggested way to remove the fork oil from what I have read, and the technique I have used when I did mine.
 

MikeN02

New Member
Interested in adding this to my collection of knowledge for maintenance to come.

I don't think anyone has hit enough miles yet to change it.
 

owldaddy

New Member
Interested in adding this to my collection of knowledge for maintenance to come.

I don't think anyone has hit enough miles yet to change it.
While I was typing my response the the question at hand, I see a link to youtube was added to the thread. Ironically I used to own a RD400C. That bike was easy to change fork oil on. While my 6R doesn't have many miles on it, I did install the Racetech cartridge emulators which required the removal and modification of the damper rods. The Yamaha oil is indeed 0 weight, and it is not the best oil I have seen in forks. I used Silkolene 10 weight in mine when I put it back together. Most any name brand oil should be better then what we got with the bike.
 

Spunky99

New Member
I already changed out my fork oil when I installed the RaceTech springs.

The stock oil is 5wt AKA 01.
I replaced it with 15wt and you put 1/2 qt in each fork tube.

You have to take the forks off and drain them.
 

Superfly

New Member
Like I posted - the debate on whether or not the Yamaha factory fill "01" is a 0 or a 5wt continues even here...

I suppose its not really important as long as the oil I'm going to replace is of a thicker viscosity...

I gave some thought as to the reason Yamaha uses such a thin oil in all its factory fills...R6s, R1s, FZ6Rs etc...and I think I know why we as FZ6R owners are stuck with the OEM oil being way too thin...

Thinking just of the adjustable forks on the R6 or R1...you can change the fork valving ie. make them more restrictive or less restrictive to fluid flow by turning adjusters. So full hard setting on compression might block 95% of the passage of oil thus making it feel hard or a great resistance....and a full out setting or soft increases the flow to say 5% blockage etc etc.

Now the thinner the fluid the less each click of adjustment would have a total effect or feel...Thin makes fine tuning adjustments possible...Thicker starting fluid might make each click too much of a jump in resistance so that you might get to a position that you cant get the right setting you want as say 2 clicks is too soft and 3 is too hard...

But with a 0 wt oil in the R1's fork your 10 or 12 clicks can dial in the perfect weight of resistance...starting with a 10wt or 15wt for example might make the fork usless for most riders or practical purposes after only 5 clicks...the thicker the oil the larger the jump in resistance each click would give you.

In conclusion I'm guessing that Yamaha just fills its forks for the FZ6R with what it normally uses for all its bikes and its up to the rider to make the adjustments. If we could adjust the valving we would crank on some resistance and be done. But we can't...the valving is fixed so we must change the fluid. And what we change in compression we have to equally change in rebound...there isnt a way to separate the adjustments...

In the end fluid changing is a much more time consuming and expensive way of tuning the front fork...
 

Spunky99

New Member
Look at the chart near the bottom of this page. The Kayaba 01 is what Yamaha uses and is listed as Yamaha 01 on live #21 right below the Kayaba.

It may be 0wt or 1wt or 5wt or whatever but it is thin. Point is that the 15wt cured the soft dampening problem.
Having to re-spring and cut custom length spacers is wayyyyyy harder than having a clicker to adjust the fork.
Having said that, does the clicker only adjust the valving/dampening or does it also adjust the pre-load? It certainly can't change the spring rate and to get the suspension right, you would still have to invest in the springs that have the correct strength for your weight on the bike.

Like I posted - the debate on whether or not the Yamaha factory fill "01" is a 0 or a 5wt continues even here...

I suppose its not really important as long as the oil I'm going to replace is of a thicker viscosity...

I gave some thought as to the reason Yamaha uses such a thin oil in all its factory fills...R6s, R1s, FZ6Rs etc...and I think I know why we as FZ6R owners are stuck with the OEM oil being way too thin...

Thinking just of the adjustable forks on the R6 or R1...you can change the fork valving ie. make them more restrictive or less restrictive to fluid flow by turning adjusters. So full hard setting on compression might block 95% of the passage of oil thus making it feel hard or a great resistance....and a full out setting or soft increases the flow to say 5% blockage etc etc.

Now the thinner the fluid the less each click of adjustment would have a total effect or feel...Thin makes fine tuning adjustments possible...Thicker starting fluid might make each click too much of a jump in resistance so that you might get to a position that you cant get the right setting you want as say 2 clicks is too soft and 3 is too hard...

But with a 0 wt oil in the R1's fork your 10 or 12 clicks can dial in the perfect weight of resistance...starting with a 10wt or 15wt for example might make the fork usless for most riders or practical purposes after only 5 clicks...the thicker the oil the larger the jump in resistance each click would give you.

In conclusion I'm guessing that Yamaha just fills its forks for the FZ6R with what it normally uses for all its bikes and its up to the rider to make the adjustments. If we could adjust the valving we would crank on some resistance and be done. But we can't...the valving is fixed so we must change the fluid. And what we change in compression we have to equally change in rebound...there isnt a way to separate the adjustments...

In the end fluid changing is a much more time consuming and expensive way of tuning the front fork...
 

Marthy

World Most Bad A$$ 6R
Elite Member

jcbrown630

New Member
I have a quart of 15wt Spectro synthetic fork oil. This enough to drain my tubes and refill? I have this leftover from the ol' oil change in the SV650S i used to have. If you think these forks are squishy ride an SV!!!!
 

Spunky99

New Member
I have a quart of 15wt Spectro synthetic fork oil. This enough to drain my tubes and refill? I have this leftover from the ol' oil change in the SV650S i used to have. If you think these forks are squishy ride an SV!!!!
1/2 qt into each fork tube is the proper amount. Combined I think the manual said .98 qt...so maybe leave a couple of drops in the oil can...LOL
 

Marthy

World Most Bad A$$ 6R
Elite Member

Spunky99

New Member
Remove the forks and the caps, turn upside down and drop out the springs and the washers at the bottom of the forks. pump the forks manually to get all the fluid out and let them sit for at least 30 minutes to drain and pump them again to make sure all the oil is out...drain some more if any fluid was left.

Pour the oil in either before reassembly and the caps or after reassembly. I added the new oil after installation of the forks onto the bike only because I needed them held in place to compress the springs and custom spacers...
That was a real hassle....20mm sag with a 215lb rider fully geared up.
 

owldaddy

New Member
Does the front fork are easy to bleed? Or all I need to do is empty, refill with oil and cap it up?
The proper way to do it is..... Take the forks off, remove the fork caps, remove the spring and spacer, dump the oil by turning the legs upside down. Replace the oil to the proper level, it is measured from the top of the leg down to the level of the oil, it just so happens a pint is 98% of that amount. I don't see why a pint can't be used, it will actually help to stiffen the spring a little. Pump the fork a couple times to get the oil in all the little nooks and crannies it is supposed to be in. reinstall the fork spring, spacer, caps and install the forks. The whole job can be done in less then an hour. It takes longer to remove the brakes and front wheel then it does to remove the forks and replace the oil.
 
W

whatever

yes over the winter now that i have a very good triple tree stand i may drop the fork oil and go thicker.

i have noticed now since the weather is in the 50 sometimes the fork action seems alittle better at times.

unless i trade it in for a fz1000r lol

i wonder if i could just remove the caps and tip the forks upside down in a clear plastic cantainer and leave overnight for all the oil to be drained.... does anybody know if that would work.
 

Bobholsopple

New Member
I've been planning on changing out the front fork oil as the rebound seems to be way to light on damping. I checked the technical manual and it states that the OEM oil for the fork is Yamaha 01 suspension oil. After reading all this:

what weight is yamaha 01 suspension oil? : Yamaha R6 : R6 Forum

And then seeing this:

Yamaha Motor Corporation, USA - Lubricants & Grease 01 Suspension Oil

I'm pretty sure that our bikes come with 0wt oil stock. I'm going to increase that up to 5wt as a starting point...

Now here is my big question: Looking at the parts schematic can I just suspend the bike in the air and then drain the oil from the fork with a drain bolt at the bottom of each fork leg? And then refill from the top hex nut cap? Am I looking at this correctly? I'm guessing that I have to remove the axle first to get at the drain bolts...I plan to do one at a time...drain the 0wt and then refill with 16oz or 475mL of 5wt...

Anyone got advise??? Thanks :)
Where did you get the oil capacity from? Is that what the service manual says? I cant find any info on capacity for the fork oil on the fz6r.
 

Marthy

World Most Bad A$$ 6R
Elite Member

Bobholsopple

New Member
It's been a while, so double check. The measurement on top of my head is 148mm from the top of the fork tube with the suspension all the way in. I ran 130mm on my FZ09 to make it more progressive and the numbers were about the same. 20W to 15W oil fork oil is what most of us used back then... 5W won't do a bit difference.
Thank you!
It's been a while, so double check. The measurement on top of my head is 148mm from the top of the fork tube with the suspension all the way in. I ran 130mm on my FZ09 to make it more progressive and the numbers were about the same. 20W to 15W oil fork oil is what most of us used back then... 5W won't do a bit difference.
4.53" is the only other measurement I found someone mention. I have to see what that converts to in mm. 5.82" is what your measurement equals in inches. I keep hearing different measurements. Never 2 the same. I cant find anyone with a service manual for our bikes, or a download anywhere for one. My fork oil is toast. I got 27,500 miles on it and it is beyond squishy, lol.
 

Bobholsopple

New Member
My forks never leaked and still dont, so mabe I'll check the stock height before I dump it and just do it that way and use 15wt. If you come across any more info let me know. Thanks for the response. By the way, your fuel maps work great. Thank you.
 


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