Fork Oil.

ja7455

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Hi, new to this forum and the NC700. Been riding KLR's for a while.
What is the proper fork oil level (cc and distance). Weight of fork oil?
Thanks
ja
 

670cc

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The answers to your questions are found in this nice write up here: Fork oil change
 
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dduelin

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Short cut - OEM is Honda SS-47 and the level is 104 mm. I would consider Honda SS-8 as well.

SAE weight is not very precise measurement of flow in light oils used in forks and shocks so it should only be used when comparing "weights" within one brand. One brands 7wt could act "thicker" than another brand of 10wt.
 

Junkie

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Interesting that Racetech's number is so far off. Their web site says to use 120mm. Maybe that's due to different springs, or the emulators, or something.
 

dduelin

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Interesting that Racetech's number is so far off. Their web site says to use 120mm. Maybe that's due to different springs, or the emulators, or something.
Yes of course it's the changes from stock forks. I'm using Cogent Dynamic cartridge emulators and an oil level of 150 mm.
 

MZ5

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SAE grade means absolutely, positively _nothing_ in fork oil. You must look at the 40C (100F) viscosity in cSt (SUS) to compare fork oils.
 

WestcoastKid

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Fork Oil Viscosity Change Question

Hey guys, I'm new to the Forum and hope I'm posting this message in the correct place.

I'd love to know if anyone has had success replacing "just" the fork oil with a different viscosity and achieved a noticeable improvement? I know there's many great threads on major fork mods, but I'd like to start with the easiest and least expensive and see if I'm happy.

Thanks much!
 

Junkie

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With damping rod forks, changing the oil weight generally gains something at the expense of something else.

If you go thicker you'll have less brake dive, but it'll be harsher over bumps.
 

WestcoastKid

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So would the opposite be true... a thinner viscosity oil providing more brake drive and a smoother suspension response over pumps.

I definitely won't be experimenting with this. Just curious if anyone has found an oil that they believe works better than the stock oil.

Thanks!
 

Junkie

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Maybe, but there's also the risk of blowing through the stroke if you don't have enough damping.
 

Fred Harper

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A question about ATF for fork oil. All my 1980's Hondas listed ATF as an alternative to Honda fork oil, the forks don't seem to be any different on the NC so is it O K to use ATF in the forks?
 

b_rubenstein

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Honda Service Manual only recommends Pro Honda Suspension Fluid SS-47 (10W). Since there is a potential material compatibility issue with fork seals an O-Rings and ATF, I would personally only use something marketed as Fork Oil.
 

MZ5

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I agree. Stick with fork oil. In addition to materials compatibility questions, fork oil and ATF have different characteristics with respect to friction, among other things.
 

showkey

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Yes .......ATF has been used as fork oil for 40 plus years.

If you google....... ATF vs Fork oil.............you will get hours of reading. With testimonials written “yesterday” that they use ATF in their bikes ( of all types). There are charts in the reading that confirm ATF is often between 5-10 weight oil. Has excellent anti Foam properties and seal and oring compatibility. No surprise since an auto trans has dozens of seals and about 50-100 orings.

So it very unlikely we will get any consensus on the controversy..............its a different version of the oil thread.


YES absolutely ........all the modern shop manuals specify fork oil.
 
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dduelin

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Really? What doe s that mean? Do you know for a fact what materials are used for those O-rings? Parker Hannifin O-Ring Hnadbook Going to pay to get the bike fixed if ATF screws up the forks?
To quote from a popular website concerned with fork oils: "For years, ATF has been the standard fluid for damper rod forks. Why? Of all the commonly available automotive fluids capable of being used in the system, ATF is manufactured within a very, very tight and suitable viscosity range, esentially ISO 34.

This means that if you are in Florida or Mongolia, AFT is going to be available and consistant. This is a very important bit of information for the mechanic.

ATF is far too thick to be used in a modern cartridge damper fork. These forks tend to use oils in the ISO 16 range."

Suspension Fluid - Pvdwiki

The unsophisticated NC700X damping rod fork is going to be just fine with ATF. For many years ATF was the fork oil of choice in many brands, including Honda and BMW. My own preference is to use Honda branded fluids If I can but I ran ATF for 40,000 miles in a BMW R100 fork after first trying a Honda product in it. The money that Bring More Wallet extracted from my wallet was not the forks but from the clutch and transmission.

To muddy the waters further, I use a 50/50 mix of ATF & 80w/90 hypoid gear oil to lubricate my chain. The ATF is good to the chain O-rings, the gear oil good to lubricate.
 

JimTid

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To quote from a popular website concerned with fork oils: "For years, ATF has been the standard fluid for damper rod forks. Why? Of all the commonly available automotive fluids capable of being used in the system, ATF is manufactured within a very, very tight and suitable viscosity range, esentially ISO 34.

This means that if you are in Florida or Mongolia, AFT is going to be available and consistant. This is a very important bit of information for the mechanic.

ATF is far too thick to be used in a modern cartridge damper fork. These forks tend to use oils in the ISO 16 range."

Suspension Fluid - Pvdwiki

The unsophisticated NC700X damping rod fork is going to be just fine with ATF. For many years ATF was the fork oil of choice in many brands, including Honda and BMW. My own preference is to use Honda branded fluids If I can but I ran ATF for 40,000 miles in a BMW R100 fork after first trying a Honda product in it. The money that Bring More Wallet extracted from my wallet was not the forks but from the clutch and transmission.

To muddy the waters further, I use a 50/50 mix of ATF & 80w/90 hypoid gear oil to lubricate my chain. The ATF is good to the chain O-rings, the gear oil good to lubricate.
Dang Dave, that is a wide range of information. You went from fluid dynamics engineering (fork oil) to shade tree mechanic with the home made chain lube. Once again very useful information. Please keep it coming. :cool:
 

MZ5

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Fork oil vs ATF: Fluid designed for the task at hand vs fluid that ‘will work, or at least appear to work, adequately.’

Gear oil is superb chain lube. It just flings everywhere, stinks like sulphur, and is a dirt magnet.
 

dduelin

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Fork oil vs ATF: Fluid designed for the task at hand vs fluid that ‘will work, or at least appear to work, adequately.’

Gear oil is superb chain lube. It just flings everywhere, stinks like sulphur, and is a dirt magnet.
Yes it is but to the latter, you’re not doing it right. My rear wheel and swing arm stays as clean as a shaft driven bike and the chain is much cleaner than it ever was using aerosol chain lubes. Having a booger of PJ chain lube fling off and stain my Aerostich was the last straw and caused me to take the advice of 50/50 ATF & gear oil.
 
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