Correct oil for GSXR front end?

Can anyone recommend or tell me what fork oil they use in their GSXR front ends on an SV650?? Its a K4 racebike running K4 GSXR 1000 forks.

Thanks,Tommy

[fastdruid]

I previously believed that USD forks should be about 5wt but it seems weight isn't good for measuring fork oil and the different oils are all measured slightly differently...
http://www.peterverdonedesigns.com/lowspeed.htm

I'd suggest going with a make and sticking with it or going with the original Suzuki Oil. Failing that the Öhlins Front Fork Fluid (No.5, #1305-01) seems to be about the right cSt.

Druid

Originally Posted by fastdruid

I'd suggest going with a make and sticking with it or going with the original Suzuki Oil. Failing that the Öhlins Front Fork Fluid (No.5, #1305-01) seems to be about the right cSt.

Druid

Has anyone actually used a different weight of oil seeing as the front forks are now supporting a V-Twin instead of a heavier inline 4??? Fork oil aint my forte

[fastdruid]

Weight of bike has nothing to do with weight of oil!

You want to change springs to match the bike (and the use) then tbh which oil is to a certain amount up to experimentation, from that link "Use the least viscous oil possible that produces good slow speed damping performance with the damping adjustment screws out 1 full turn from full closed."

If you want to copy someone else then just going by weight is no use, you need to use exactly the same make of oil too.

Druid

Originally Posted by fastdruid

You want to change springs to match the bike (and the use) then tbh which oil is to a certain amount up to experimentation

Im doing this on a shoestring mate so springs wont be getting replaced this season anyway unless I win the Lotto Im opening the forks up to machine back my preload spacers so I decided I may aswell change the oil while Im at it. Static sag is to be set at 25mm but I cant achieve this even with the preload backed off fully so im gonna have it in such a way that when I have 25mm static sag ill be in the middle of my preload adjustment. Make sense

[fastdruid]

Hmmm, you really want to get the right springs but K4 I believe should be 0.85Kg/mm which *should* be about right, if anything a touch soft so you are going the right way about it by reducing the preload.

Put your actual weight into this
http://old.racetech.com/evalving/Spr...pringType=Fork

And it'll tell you what it should be. I tried it with 80Kg and it suggested 0.9Kg/mm which isn't a million miles away from what you have.

I'd suggest you go with Suzuki fork oil to start with.

Druid

Originally Posted by fastdruid

Hmmm, you really want to get the right springs but K4 I believe should be 0.85Kg/mm which *should* be about right, if anything a touch soft so you are going the right way about it by reducing the preload.

Put your actual weight into this
http://old.racetech.com/evalving/Spr...pringType=Fork

And it'll tell you what it should be. I tried it with 80Kg and it suggested 0.9Kg/mm which isn't a million miles away from what you have.

I'd suggest you go with Suzuki fork oil to start with.

Druid

Recommended Fork Spring Rate for Racing: 1.038 kg/mm (use closest available)
Stock Fork Spring Rate: .850 kg/mm (stock)

Not a million miles away either so Ill carry on as Im going and change the oil. Im sure Ive a few gallons of Rock Oil racing fork oil somewhere.I won it at a raffle at the Manx GP in 07 Ill check what WT it is

[fastdruid]

Hmmm, how did you get a different "stock fork spring rate"? I got the SV as being 0.67

Did you run it for the GSX-R1000K4 rather than the SV650?

Druid

Originally Posted by fastdruid

Did you run it for the GSX-R1000K4 rather than the SV650?

Druid

I did.

[fastdruid]

You want to run it for the SV, the fork spring rates are relative to the bike not the forks.

Druid