Fork Oils

[scdmarx]

And good info it was. Thanks for taking it further.

I would like to add something I got from Kevin McCartny over on iATN:
"Different fluids have different kinematic viscosity,
different dynamic viscosity, different material
compatability, different foaming properties/additives,
different seal conditioning prperties/additives, different
shear properties/additives, etc, etc, etc"

I agree with you about ATF being a better gas additive than P/S fluid. I think mostly for the detergent properties. But after reading and pondering Kevins statement, I'm wondering if maybe P/S fluid might do better as fork oil than ATF? Think about this, we know P/S fluid is made to take some heat, (many cars have P/S fluid coolers) It's a hydraulic fluid made to be pressurized, it's made to resist foaming, but I'm thinking along the line of the type of seals and bushings in the fork tubes, and how they might resemble the seals and bushings found in power steering rack & pinions. Pumping, road shock, and all. Obviously the best oil for the application would be "fork oil", but ATF being a satisfactory cost efficient alternative, would power steering fluid be a better alternative for the given application? Or do you still think ATF would be better? I don't know, I'm just bouncing this off you. I am currently using ATF in my shocks.


(Posts moved from ATF in Fuel topic....to continue the discussion about oils used in front forks.)AApple

 

[AApple]

It's a little off-topic, but....I think you may be on to something there. Forks wouldn't need the complete additive package in the ATF, and the PS fluid would seem to be more suited to the job at hand, depending on viscosity ....interesting concept. :yes:

 

[mcgovern61]

It's a little off-topic, but....I think you may be on to something there. Forks wouldn't need the complete additive package in the ATF, and the PS fluid would seem to be more suited to the job at hand, depending on viscosity ....interesting concept. :yes:

A little off topic makes it "TOPIC WORTHY"! I suggest the last few posts are cut and moved to a new topic, "Fork Oil".

 

[bk2valve]

Thanks for this thread and the info from all. I had not been doing this but just started doing it as a result of you-all's experience...
.
Currently I have a liter or so of MMO I had used some of for a different app, so I am using that until it is gone then will likely switch to ATF.

Until the last few posts get moved to a different thread, I will add a comment here regarding forks.

I was told that while it will work, ATF is a poor fork oil in that the viscosity requirements are too broad. In other words the most it can be is 10W but it is not guaranteed to be that depending on the brand and the manufacturing run, etc. I do not know for sure if that is true but what I was told by an independent bike mechanic.

I use 15w fork oil in my forks at the moment. Only because I live in bumdoodle New Mexico where there was no other varieties of fork oil available....(my manual calls for 20W fork oil) and since I am hauling a hack, I wanted a high viscosity fork oil. .I will go with this until next fork oil change and switch to the higher viscosity. Incidently, I have progressive springs in the forks with the air over that...

Anyway....interesting topic and I would enjoy reading what you all think about it and what you do....
Brian

 

[mcgovern61]

Until the last few posts get moved to a different thread, I will add a comment here regarding forks.

I was told that while it will work, ATF is a poor fork oil in that the viscosity requirements are too broad. In other words the most it can be is 10W but it is not guaranteed to be that depending on the brand and the manufacturing run, etc. I do not know for sure if that is true but what I was told by an independent bike mechanic.

I use 15w fork oil in my forks at the moment. Only because I live in bumdoodle New Mexico where there was no other varieties of fork oil available....(my manual calls for 20W fork oil) and since I am hauling a hack, I wanted a high viscosity fork oil. .I will go with this until next fork oil change and switch to the higher viscosity. Incidently, I have progressive springs in the forks with the air over that...

Anyway....interesting topic and I would enjoy reading what you all think about it and what you do....
Brian

Very interesting.....ATF vs different weights? I wonder which gives the best performance (smoothness)?

 

[AApple]

Otay...new topic created.... k:

I have always heard, and been told, that ATF is a 30 wt oil. Seems a little thin to be 30, but....that's whut I've always thought it was. Might be interesting to find out for sure. :read:

 

[bk2valve]

I would be interested in any real info guys turn up on the ATF...I am nearly certain it is no more than 10w but would be good to know if what I was told about varying weights is true....

Brian

 

[mcgovern61]

When I replaced my fork seals, the information that I got (I think in my Haynes or Clymer manuals) said to use ATF.

 

[scdmarx]

I've always heard, and assumed ATF was 10wt. It's VERY thin when compared side by side with 30wt motor oil. But there's so many different blends of ATF now, I wonder if it's all the same wt? Some Honda transmissions use 5w30 motor oil. Then there's the CTV blend. It's really getting quite complicated.

But still a very interesting question: What effects will different weights have in our shocks? Seems to make sense to me that thicker would be a harder ride, or for heavier weight. But I really wouldn't know.

 

[dan filipi]

I found that 20 wt fork oil most definitely gives a harsher ride than ATF.
The ATF I use is just the cheapest stuff I can find. I haven't seen any difference in viscosity thru the years, maybe color though but that probably just added?

 

[bk2valve]

When I replaced my fork seals, the information that I got (I think in my Haynes or Clymer manuals) said to use ATF.

I think I should have been a bit more clear....I was quoting the info from the sidecar section of my Clymer manual....I just assume people know I am talking about a sidecar rig...I don't have anything else.
Bri

 

[scdmarx]

When I replaced my fork seals, the information that I got (I think in my Haynes or Clymer manuals) said to use ATF.

I think I should have been a bit more clear....I was quoting the info from the sidecar section of my Clymer manual....I just assume people know I am talking about a sidecar rig...I don't have anything else.
Bri

Yes, that's the way I understood you. I thought you were clear about having a sidecar.

 

[bk2valve]

Yes, that's the way I understood you. I thought you were clear about having a sidecar.

Ok great thanks for the input....sometimes I am only clear in my own mind .. :thanks:

Brian

 

[mcgovern61]

When I replaced my fork seals, the information that I got (I think in my Haynes or Clymer manuals) said to use ATF.

Checked both Haynes and Clymer and they say to use ATF. Back when I did my seals (many moons ago it seems like, or maybe just three years) I only had access to these manuals and the Saunders site. Following Dan's posts at the time on the Saunders site led me here when it was first up and running! (Before the crash) :music: :music2:

 

[macka]

Talking with the guru at the mill, he says both are between 5 and 10 weight depending on manufacturer, and CVT is 12 to 15 with a more aggressive add pack (additives) which will make a ride a lot less fun.

 

[src68]

im trying to read as much info as possible about bikes and things.. especially the things that are effecting my bike.

i read the whole thread and it just says ATF is this reg. ATF used in cars?? or is there a special motorcycle ATF..
thx and what brand is the best.
thx again

 

[mcgovern61]

im trying to read as much info as possible about bikes and things.. especially the things that are effecting my bike.

i read the whole thread and it just says ATF is this reg. ATF used in cars?? or is there a special motorcycle ATF..
thx and what brand is the best.
thx again

Just good old fashioned ATF. I had some Dextron II laying around that I used and it has worked fine for 3 years. (Plus any left over goes into the gas tank 8 oz per full tank to keep the carbs working right!)

 

[89-300ce]

https://www.advrider.com/forums/showpost ... ostcount=6

 

[AApple]

https://www.advrider.com/forums/showpost.php?p=12561208&postcount=6

Interesting...just about the exact same discussion as we had here, but more specific info.
Ya needs to read the entire thread, tho. :good:

 

[Omega Man]

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