Yamaha suspension Oil

Hi can someone tell me what weight the yamaha suspension oil 01 is?

I believe it is 7.5wt or medium weight. This weight is also known as 125/150 vrs. the 85/150 that is 5wt.

thanx I have a bunch left over and i was wondering if i could use it in my fox fork for my mountain bike they recommend 7.5wt or 5wt....so maybe i don't have to go out and spend another 20 bucks on fork oil for the mtn bike :thumbsup:

I thought it was 5 weight


Suspension fluid "01" has never had its viscosity listed. As far as I know, it's 5wt.

Well this is why I thought it was a 7wt. From MXA article called 'The Secret World of Fork Oil'. I'm only copying in one question pertaining to this but rereading it I'm more confused than before, anyway;


This is where not having a finely calibrated oil weight rating scale confuses matters even more. Some mechanics claim that Kayaba 01-labeled a 5wt-is thicker than Showa SS-7 (and other 5wt cartridge fork fluids). They call it a "thick" 5wt or claim that it is really a 7wt. But, if you call Kayaba they will tell you that Showa's SS-7 is thicker than 01 oil.

Unfortunately, you have no choice but to let them call it what they want. The rule here is to find a reputable 5wt cartridge fluid that works best for you. When you find a fork oil that delivers the performance you want, stick with that brand. Just to clear the record, Showa SS-7, Kayaba 01 and Pro Circuit PC-01 are all produced by the same company in Japan. Except for color, they are the same weight oil.

The truth is that in modern suspension systems, minor differences in oil viscosity don't matter that much. The valving works as a pressure regulator, controlling the balance of pressures on either side of the valve as the pistons move through the fluid. If the fluid is thicker, the valve simply opens more. Obviously, there's a limit, but you have to realize that the viscosity shift in a typical suspension fluid between between 70 and 140 degrees is greater than the difference between a 5 and a 10 wt.

When oil is forced through a control orifice, viscosity does matter, and this is why you will need to open the clickers a little to compensate for heavier oil, but after that, there's not too much difference between one step and the next.

I don't know how to copy in a PDF but this chart is quite interesting on the viscosity of fork oils at 40C and 100C. It is found at peterverdonedesigns/com/files/suspension%20oils.pdf search for 'suspension%20 oils'.

thanx I have a bunch left over and i was wondering if i could use it in my fox fork for my mountain bike they recommend 7.5wt or 5wt....so maybe i don't have to go out and spend another 20 bucks on fork oil for the mtn bike :thumbsup:

I put yamaha 01 in my fox RLC float 100 been in there for at least a year with no problems

(from MXA)

This is where not having a finely calibrated oil weight rating scale confuses matters even more.

If you have one, it doesn't necessarily help. The viscosity grade of an oil is a range, not a fixed number. In motor oils, for example, 40 wt runs between 16.3 centistokes (cSt) and 12.5 cSt. A 30 weight is between 12.5 and 9.3 cSt. In a case where viscosity was an issue, the difference between a 40 at 12.9 and a 30 at 12.2 would be much less than between two 40's at 13 and 16 cSt.

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