2018 KYB Oil alternative

eralha

New member
Hi,

Planing on doing fork maintenance, saw on the manual that the recomended oil is KY B 01M Oil, what would be an alternative oil from other brand like motul?
Motul fork oil 5w?

Thanks.
 
Motul Factory Line 5W is very close on viscosity to the KYB oil and I have used it successfully in a number of different fork makes.
 
Has anyone tried 2.5w in their 18/19 kyb forks?

Yep, inner carts get 2.5w,outer get 5w.
I?m using maxima 3w in the inner cartridge,cst is 4.8@100 Celsius and 14.8@40c.
Fantastic in rear shock too but at 50hrs,requires replacing.
 
Yep, inner carts get 2.5w,outer get 5w.
I?m using maxima 3w in the inner cartridge,cst is 4.8@100 Celsius and 14.8@40c.
Fantastic in rear shock too but at 50hrs,requires replacing.

How would you describe the effect of the 2.5w?

I've heard of guys using a (lighter) 1.0 ICS spring; does this do something similar?

Jeff
 
Yep, inner carts get 2.5w,outer get 5w.
I?m using maxima 3w in the inner cartridge,cst is 4.8@100 Celsius and 14.8@40c.
Fantastic in rear shock too but at 50hrs,requires replacing.

Ive been using 2.5 wt as well, Motorex & now Maxima 3wt in both forks and shock in last revalve.
Why 5wt in the fork outers?
 
The Maxima 5w is close to the KYB viscosity.

I saw some posts on TT that said lighter viscosity oils like 2.5w reduces dampening which is a common tuning tool, but it can create other issues when the light oil gets hot and further reduces viscosity.

You can put different oil in both chambers, but over time the inner and outer chamber oils mix and blend together.
 

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you would be doing a lot of trial and error if you do not know their viscosity. So many other variables with suspension rather just stick with one oil
 
The options are ATF or hydraulic fluid.

Not sure on the viscosity of various ATF brands but hydraulic fluid is fairly simple as the ISO standards equate to specific oil weights. For example the ISO 22 oil is equivalent to 5w oil.

Hydraulic fluid is WAY less expensive than fork oil. Like WAY less expensive.
 
Hydraulic fluid is less expensive. But if you try finding correct synthetic hydraulic fluid, things get much more expensive and are usually sold in bulk.
If mineral is fine, then no problem.
 
just going off the sales pitch of suspension oils, does the ATF have the non foaming properties of suspension oil? and also longevity (and consistency iro not fading) of being forced through valves multiple times per second

I don't know the answers, but just two questions i would be trying to find answers for
 
I am going to try some of the Amsoil 5w light Shock Therapy suspension oil.
 

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just going off the sales pitch of suspension oils, does the ATF have the non foaming properties of suspension oil? and also longevity (and consistency iro not fading) of being forced through valves multiple times per second

I don't know the answers, but just two questions i would be trying to find answers for

I was an engineer with GM's Hydra-matic (aka, High-dramatic) automatic transmission division in the 1980s. I spend alot of time with ATF.

1. Yes, ATF has anti-foaming agents. Foam entrains air in ATF, which reduces its bulk modulus (stiffness), which affects clutch timing (rate of engagement/disengagement) as the fluid "pushes" against a spring. Automatic transmissions have significant spinning elements, all of which work to "whip" the oil. Foam also causes pump cavitation, which causes excessive wear on the pump as well as adversely affects shift quality. Foamy oil is very detrimental to performance, so anti-foam elements are added to everyone's formulation.

2. ATF also has to deal with the pump, pressure regulator/relief valve, and the valves which operate in the valve body. All of those operate at relatively high frequency (pumps at much higher frequencies) than oil passing through a shim stack, so a suspension application won't pose a problem for forks/shocks.

ATF also contains solvents/detergents which keep the hydraulic valves in the transmission clean, free from sticking, and generally happy. That will work to keep your shim stack clean.
 
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