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ya i already know that... just got done reading for the last 15 mins about all this... its just another designation for how a oil flows/characteristics/designation.... its all mashes together in the bottle. lol guess maybe they just call it that to make it simpler for people... ??? weight is thrown around in all the reading i did ALOT but nothing that really said why WEIGHT was used......but yes they did explain viscosity...which i already knew....
but one way or another it can still be used in forks as long as ya find the right "viscosity"-"weight" ....... atf is used in motorcycle forks all the time.. no different than engine oils.... will all protect the internals and flow as needed if the right "weight/viscosity"
 

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Meh.
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In my opinion, weight is the wrong terminology as it holds a different meaning.

ATF may contain seal swellers that could damage the seals. And again... it could foam up.
 

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No Fear
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I dont khow but it ruined the bushings in my RC2X and made me to trow it away .
i wont make that mistake again. I used STP synthetic motor oil. But now i use Fox ' Sram suspension fluids wich are now available over here in Iran. Or some times Citroen LHM plus mineral.
 

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Discussion Starter #24
so motor oil is ok for forks with open bath system? How about motor oils used in rear shox? any comments?
 

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as said above if you can get FORK OIL its gonna be the best way but if not then MOBILE 1 ATF seems to be a good substitute that im reading about.....
where are you located that you cant get fork oil ? like someone else said just order it off the net since you have access....
 

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XSL_WiLL said:
Explain... Viscosity has nothing to do with weight. Viscosity is a fluid's internal resistance to flow. Viscosity is measured in centistrokes.

The w in 5w30 is not for weight, it's for winter.

And labeled viscosities (such as Torco RFF 7 vs Rockshox 5 being the same viscosity) are hardly an accurate measure of viscosity.

I imagine that using motor oil in a damper may cause foaming as well. And most motor oils are multi-viscosity. A fork or shock can build up quite a bit of heat.
Weight and viscosity are interchangeable terms when it comes to oil, but thanks for being hoity toity about it with the rest of us, Terminology Nazi.
 

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Meh.
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rmb_mike said:
Weight and viscosity are interchangeable terms when it comes to oil, but thanks for being hoity toity about it with the rest of us, Terminology Nazi.
Weight and viscosity have different meanings... this is true to any fluid, not just oil. Weight is a misused term. This is what I have always been taught. Wikipedia each... they're different. Weight is never mentioned or used in the viscosity article, and vice versa. This is also true in my text books.

Still bitter that I called you out on your SPAM? Get over it. You don't have to be an ass for me trying to clear up some confusion.
 

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Wow some crazy info in here.

Don't use ATF as it has friction modifiers to help the transmission bands grab. We don't need any more friction.

Viscosity describes a fluids thickness, and doesn't translate well unless measured at the exact same temperatures and measures. 7w(weight) fork oil at 20 degrees could be thicker than 5w30 motor oil at 80 degrees. If you live in cold temps don't use thicker oils than spec, and if you live in hot climates you can play around.

Almost all oils these days have anti foaming properties, so motor oil won't foam more than a true suspension fluid. If there is air in the system, you are gonna get foaming.

If you can't find suspension oil, a thin hydraulic oil(tractors-equipment) is almost the same stuff. In fact, I'm 90% sure most suspension companies buy normal, but good quality hydraulic fluid, and re-bottle it or use in their suspension.
 

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Meh.
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The SAE classifications characterizes the viscosity at low and high temperature of the lubricant. The grade is given by two numbers separated by the letter W (meaning winter).

Neither number corresponds to an actual 'weight,' even though that is the term most people use when referring to motor oil. The viscosity (flow resistance) is tested by allowing a small amount of oil to flow through an aperture. The quicker the oil flows, the lower the rating numbers.

The first number rates the viscosity of the oil at a temperature of 0 degrees F, mimicking cold winter weather, which is why the 'W' designation is added at the end of the first number. The second number repeats the test at 210 degrees F., or normal operating temperature for a fully-warmed engine.
 

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Nice one Will, I always wondered how that worked. Seems so simple now I think I will go clean my chain.
 

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this is old and maybe i can get a reply from someone..... what about brake fluid. Its a hydraulic fluid and it is definitely thinner than engine oil or tranny oil. Would it be too corrosive?
 

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sicktim said:
this is old and maybe i can get a reply from someone..... what about brake fluid. Its a hydraulic fluid and it is definitely thinner than engine oil or tranny oil. Would it be too corrosive?

man oil is available online....it is under 25 bucks and last 3 or 4 oil changes...get the right stuff and don't mickey mouse stuff
 

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sicktim said:
this is old and maybe i can get a reply from someone..... what about brake fluid. Its a hydraulic fluid and it is definitely thinner than engine oil or tranny oil. Would it be too corrosive?
Or, or, or, how about canola oil? since it is still a fluid...
 
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