fork oil weight?

2005 yz 450, the manual says to use yamahas sp1 fork oil, what weight is that so i can get some other brand? its like 40 bucks a can plus i need just over one when replacing the oil. seems like they know how to stick it to you.



No one has ever been able to definitively answer the question of what the viscosity of Yamaha S1 is, but any good fork oil in 2.5-5wt will do. Amsoil Shock Therapy is one of the better conventional oils, as is Motorex.

Viscosity doesn't matter as much as many believe, since fork valving is essentially a pressure regulation system, rather than a bunch of controlled orifices. The viscosity shift between 70 and 160 degrees oil temp is about 3 times greater than the difference between 3wt and 7wt, anyway. After you make a couple of clicker adjustments for the different oil, they will more or less behave the same across a wide viscosity range.

Some, including myself, like to run a heavier oil in the outer chamber to improve the performance of the bottoming brakes while running a little lower oil level for better overall feel.

The best oil you can use, IMO, is a rather unconventional product from SMART Performance: 215.VM2.K5. Use the lighter SP3 in the inner, and SP5 in the outer.

thanks for the reply, i have asked many people and shops this question and this was by far the best reply i had recieved.

He isnt called GrayRacer for no reason! When you have been alive for 60yrs you tend to pick up some useful info along the way! :banghead:

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