Anybody use 7.5wt fork oil

8 replies to this topic
  • John_in_Long_Beach

Posted July 20, 2000 - 09:00 PM


Anybody use 7.5wt fork oil? instead of the Yamaha 01 (which is generally believed to be 5wt.

Thanks for your comments

  • fershy

Posted July 20, 2000 - 09:09 PM


yeah I have on occasion mixed a bottle of 10W Fork oil with a 5W. Works quite well

  • jj

Posted July 21, 2000 - 06:42 AM


Those damn dealers! I've been told that "01" is everything from 2.5-10 weight, it all depended on what dealer I called...
Personally I think your're right, it is 5 weight.
I went ahead and changed my oil to Golden Spectro 125/150 (7.5 weight) when I replaced my fork seals. People think I'm crazy, but I really do feel like my suspention feels smoother, more plush. I guess it could be me just wanting to believe...I can tell you it defintely doesn't hurt!

JJ - 99 WR; WR timed, stock jetting, Scotts stabalizer, Scotts triple clamps, Pro-Tapers, Terry Cable Hot start, MSR Raptor clutch lever, Moose skid plate, Works frame guards, Acerbis Pro Rally guards, Renthal MD-soft grips, Russel speed bleeders, Factory Effect graphics, YZ rear fender

  • John_in_Long_Beach

Posted July 21, 2000 - 07:18 AM


Thanks for the comments guys. The lack of informtion, or should I say the shear amount of misinformation in this area is astounding.

My thought was if I wanted more dampening to go to a thicker oil. But how do you go thicker if you don't know what you have.

Then there is this bullshit about only being able to use the 01 oil, because it is so f***ing special.

Well I had two quarts of Spectro 7.5 wt ready to go, when I bought into the bull about using only 01.

Actually I figured it would be better to have a controlled experiment and only change one variable at a time (going with the higher fork oil level).

So for now I will try the higher level with the 01.

Then if I need more dampening, I will have to decide......

Do I revalve or go with thicker oil.

I am glad to hear about your experience with the 7.5 Spectro.

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  • John_in_Long_Beach

Posted July 21, 2000 - 07:33 AM



You mentioned smoother.

Do you mean less stiction, because the oil is a synthetic and there is less friction on the seals for the initial travel.

Or Do you mean less dampening, because the oil is actually thinner.

The reason I ask. I held off on the 7.5 wt partly because I compared the thickness of the 7.5wt with the stuff coming out of the fork and it didn't seem any thicker.


What I was told by Beach Yamaha is that the reason there is no wt. spec for the 01 oil is that it is not oil but "hydraulic fluid" or some other substance that doesn't go by the grading systems of the oils.

Part of me thinks that this is just a bunch of Mumbo Jumbo that keeps the fork tuning guys in the business.

I have an mechanical engineering degree, so I am not intimidated by technical stuff, in fact I generally like to understand how things work and do my own work.

My observations with the Hi Perf industry is that there are not many really technical people, so what the "industry experts" like to do is baffle us with bullshit, so they make their contributions seems worthwhile and mysterious, while they really may have no clue themselves.

Kind of like the "Wizard of OZ" is only a frumpy old man behind the screen.

Thanks for letting me get that off my chest.

  • Kevin_in_New_Hampshire

Posted July 21, 2000 - 07:40 AM


John in LB,
I absolutely agree w/ you on the Baffle w/ BS. I think the OEM mechanics have to sign some statement saying "I will uphold the use and only the use of of all (fill in the OEM manufacturer) factory fluids in this machine until death do us part" or something like that.
What the motorcyle and motor oil/oil industry is most afraid of is someone aking "Why?", kind of like government stuff.

99 WR, all YZ mods, de-octopused, OEM YZ tank and IMS seat, jetting by Clark, got forked by Pro Action, WAITING IMPATIENTLY FOR MOAB!!

  • jj

Posted July 22, 2000 - 07:36 AM


Hey John. I'm not totally sure what I mean... Sorry it's hard to describe. I guess I do mean less stiction (smoother operation). There is definately not less dampening. In fact my clicker postion did not change. Interesting... My compression is set at 9 and my rebound is at 8. I weigh about 210 and ride pretty aggressively. I dont ride MX and thus dont bottom much. I ride mostly tight, tough, rocky, rutty, muddy single track. It really feels like these forks were made for me, they work incredibly well.
The most knowledgable guy I've talk to about YZ/WR suspention is Steve at White Brothers. He really impressed me with is no Bull Sh** answers and his overall knowledge. His recommendation was to go 105mm with the Golden Spectro 125/150 (7.5 weight). He's batting 1000.... :)

JJ - 99 WR; WR timed, stock jetting, Scotts stabalizer, Scotts triple clamps, Pro-Tapers, Terry Cable Hot start, MSR Raptor clutch lever, Moose skid plate, Works frame guards, Acerbis Pro Rally guards, Renthal MD-soft grips, Russel speed bleeders, Factory Effect graphics, YZ rear fender

[This message has been edited by JJ (edited 07-22-2000).]

  • John_in_Long_Beach

Posted July 22, 2000 - 09:03 PM



Thanks for the input.

If White Brothers uses 7.5 weight then it should be ok.

I was told by a Yamaha dealer, who had good connections, absolutely under no conditions use anything else by Yam 01.

Seems like you and White Bros have proved them wrong.

I went with 100mm and Yamaha 01 for this first go around. I will get a chance to try it this weekend. I think I am going to see a big difference.

But I guess the moral of your story is don't believe all of the BS hype you hear.

Thanks for the input.


  • Guest_Guest_*

Posted July 24, 2000 - 12:55 AM


I'm 220-30lbs in all my kit i have 4.4 springs 135mm oil height, comp' and rebound ajusted acording to where i'm riding usually only a few clicks from standard. I use 7.5wt fork oil (50/50 mix of 10 and 5wt oil). This set up works great for me (mainly woods with the occasional practise at a MX track).


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