Can someone define fork oil weight for me

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motofox2006
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Can someone define fork oil weight for me

Post by motofox2006 »

what does fork oil do, I think it slows down the rebound dampning, am I right can someone please state what it does.

For my 91 kdx should I use recommended 10wt oil or 7wt which is what most people are using, I ride deep sandy whoops with .35kg springs..
E series 91 KDX
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canyncarvr
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Post by canyncarvr »

Fork oil is the blood of your hydraulic suspension system. It effects both compression and rebound actions. With no restriction to movement (no oil) the whole mess would just boing-boing back and forth...up and down..whatever.

On an OEM set of forks (there being NO rebound adjustment) oil viscosity is the ONLY thing that 'controls' rebound.

I doubt you would notice much if any difference between 7 and 10 weight. Not saying there IS no difference, but it's not going to be huge.

You are correct...thicker oil will slow fork rebound.

Compare water vs: molasses sucked through a straw........

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KDXer
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Post by KDXer »

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Post by canyncarvr »

Thanks for the re-link, Mr. KayD. I hadn't seen that.

Curious..Mobil1 ATF is listed with a cSt@ 100ºC of 7.60??!! That fits an SAE motor oil grade of W-20!!

..not that forks run that hot..but it happens to be the temp rating used in the comparison chart.

At 40ºC Mobil1 cSt 34.00. That's hard to believe.

But..the difference 'tween parabolic and cone type LSC adjusters is similar. Who'da thunk such a thing.

'Spension gerus, I guess.

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