Fork Oil Question
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My friend had an old '82 Goldwing ,and we changed the fork fluid with factory recommended fluid. Automatic trans fluid. I bought Harley's "genuine" fork oil for my '96 Harley and it looked and smelled just like automatic trans fluid. So, I wouldn't spend much on "special" fork fluid as it doesn't seem worth it to me.,,,
The synthetic damping oils are usually labelled "shock oil". They retain their viscosity better with temperature changes which is more important in a shock (less oil volume, heavier damping due to leverage ratio acting on the shock, not in direct airflow).
I've heard people say that shock oil doesn't have the same anti-foaming agents as fork oil as it isn't a needed property in a shock due to the oil and air being kept separate. I've also heard this isn't true and shock oil will work fine in a fork.
I've heard people say that shock oil doesn't have the same anti-foaming agents as fork oil as it isn't a needed property in a shock due to the oil and air being kept separate. I've also heard this isn't true and shock oil will work fine in a fork.
Originally Posted By: magic
Hi lads, long time reader only signed up.
Question is regarding fork oil.
What would be the advanages of using a fully synthetic fork oil over normal fork oil.
Use my bike on the road but do the odd track day.
Thanks guys.
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too. Other than water infilteration, why would you ever need to change it?
Hi lads, long time reader only signed up.
Question is regarding fork oil.
What would be the advanages of using a fully synthetic fork oil over normal fork oil.
Use my bike on the road but do the odd track day.
Thanks guys.
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too. Other than water infilteration, why would you ever need to change it?
Have you ever seen old fork oil? Dust and dirt will slip by the seals. Most fork oil is clear or Amber coloured. It usually comes out dark brown or black.
Originally Posted By: magic
Hi lads, long time reader only signed up.
Question is regarding fork oil.
What would be the advanages of using a fully synthetic fork oil over normal fork oil.
Use my bike on the road but do the odd track day.
Thanks guys.
Higher VI. More consistent damping over temperature changes.
Hi lads, long time reader only signed up.
Question is regarding fork oil.
What would be the advanages of using a fully synthetic fork oil over normal fork oil.
Use my bike on the road but do the odd track day.
Thanks guys.
Higher VI. More consistent damping over temperature changes.
After hundreds of thousands of miles on different bikes. I have found that synthetic fork oil will hold its viscosity much longer than normal fork oil. And yes it does break down with miles. Another thing I always did was to go the next viscosity higher than recommended. It would be a little stiffer at first but within 500 miles it felt perfect. I realize that most are pretty much rated standard duty or heavy duty ect. At least from the dealer I was buying from. I always opted for the heavy duty.
[/quote]
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too.
Other than water infilteration, why would you ever need to change it? [/quote]
Internal friction from the springs and bushings contaminate the oil quite a bit.
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too.
Other than water infilteration, why would you ever need to change it? [/quote]
Internal friction from the springs and bushings contaminate the oil quite a bit.
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lots of completely stupid responses above.
1) forks have so much surface area that they never get hot enough to ever "claim" they need a higher temp range. this has been proven is SX, MX and GNCC where the forks actually move more than 1". a shock is a completely different beast.
2) fork oil starts breaking down the instant it is poured out of the bottle and into a clean fork. regardless of if it is dino or synth.
3) the shims (both compression and rebound) that are made of steel, grind themselves into a fine powerder into the fork oil and can be detected in as soon as 5hrs of fork operation. realize that is oil is also what lubes the inner tube as it slides in the teflon coated bushings.
4) forks rarely provide enough "wear" on the oil to actually cause it to shear out of grade.
5) Mobil 1 ATF has been proven to be a very very good fork oil at the upper end of the thickness range of viscosity.
6) fork oil comes in many different weights (0 -> 10+) and greatly effects the fork action on both compression and rebound.
i have done a UOA on a kyb fork. has anybody else posting actually done that? yeah, i bet not.
1) forks have so much surface area that they never get hot enough to ever "claim" they need a higher temp range. this has been proven is SX, MX and GNCC where the forks actually move more than 1". a shock is a completely different beast.
2) fork oil starts breaking down the instant it is poured out of the bottle and into a clean fork. regardless of if it is dino or synth.
3) the shims (both compression and rebound) that are made of steel, grind themselves into a fine powerder into the fork oil and can be detected in as soon as 5hrs of fork operation. realize that is oil is also what lubes the inner tube as it slides in the teflon coated bushings.
4) forks rarely provide enough "wear" on the oil to actually cause it to shear out of grade.
5) Mobil 1 ATF has been proven to be a very very good fork oil at the upper end of the thickness range of viscosity.
6) fork oil comes in many different weights (0 -> 10+) and greatly effects the fork action on both compression and rebound.
i have done a UOA on a kyb fork. has anybody else posting actually done that? yeah, i bet not.
Originally Posted By: philipp10
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too. Other than water infilteration, why would you ever need to change it?
You'd think there wouldn't be any change, but... After a couple of years use a change of oil will make a noticeable difference in feel (plusher and more controlled).
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too. Other than water infilteration, why would you ever need to change it?
You'd think there wouldn't be any change, but... After a couple of years use a change of oil will make a noticeable difference in feel (plusher and more controlled).
I just recently did a fork service on my GSX-R750. The oil was filthy. Lots of fine sliver glitter in it and grey milky colour. About 100k klms on the forks.
Using Silkolene PRO full synthetic. I don't know if it has a good VI, but I do have to turn the damping screws out a full turn for winter as the damping becomes way to firm with the cooler temperatures. Always having to fiddle with the damper screws. Not much better than OEM IMO.
Going to try Ohlins oil next time. Or maybe ATF if the viscosity is near a 10W. Doubt it.
Using Silkolene PRO full synthetic. I don't know if it has a good VI, but I do have to turn the damping screws out a full turn for winter as the damping becomes way to firm with the cooler temperatures. Always having to fiddle with the damper screws. Not much better than OEM IMO.
Going to try Ohlins oil next time. Or maybe ATF if the viscosity is near a 10W. Doubt it.
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Originally Posted By: philipp10
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too. Other than water infilteration, why would you ever need to change it?
Seriously???? My dirt bikes get their fork oil changed annually. The bigger adventure bikes, every other year.
Every time I buy a used bike, maintaining the forks is a top 5 on my list of work to do. And I have poured out the nastiest snot you could imagine. Forks need maintenance.
My buddy down the road, works on trophy trucks, desert racing vehicles, etc. These are the rigs with 24" of suspension and massive shocks. On the trucks he regularly maintains, he does shock maintenance annually. He buys synthetic 5w by the 5 gallon jug for about $75. I fill up my 1 gallon jug and hand him a $20 bill. He says fork oil that is $20 a quart is the most horrible version of highway robbery on the market.
I suppose if one owns the proverbially cruiser (no need to mention a brand), and the scooter hauls their a$$ to the bar and back on the weekends....then no need to worry.
In my opinion, using synthetic would be a complete waste of money. And to be honest, changing your fork oil seems like a waste of money too. Other than water infilteration, why would you ever need to change it?
Seriously???? My dirt bikes get their fork oil changed annually. The bigger adventure bikes, every other year.
Every time I buy a used bike, maintaining the forks is a top 5 on my list of work to do. And I have poured out the nastiest snot you could imagine. Forks need maintenance.
My buddy down the road, works on trophy trucks, desert racing vehicles, etc. These are the rigs with 24" of suspension and massive shocks. On the trucks he regularly maintains, he does shock maintenance annually. He buys synthetic 5w by the 5 gallon jug for about $75. I fill up my 1 gallon jug and hand him a $20 bill. He says fork oil that is $20 a quart is the most horrible version of highway robbery on the market.
I suppose if one owns the proverbially cruiser (no need to mention a brand), and the scooter hauls their a$$ to the bar and back on the weekends....then no need to worry.
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I agree with you John. I believe fork maintenance is important. I would always immediately change out that Fish oil [censored] Showa puts in the Harley forks. It looks and smells like s+*t. Forks were immediately better also. It was a 1 hour job on the HD. Different story on the Indian, but I will be doing it this winter.
wait...Showa is a japanese company. O M G you mean a harley has made in japan parts on it? how un-american!!!
and yes i knew this in the late 80s. along with that german made bosch ignition.
the usa has an import tarrif/ban on japanese products that contain grease/oil (at least on motorcycles) and they barely contain enough grease/oil to prevent rust
and yes i knew this in the late 80s. along with that german made bosch ignition.
the usa has an import tarrif/ban on japanese products that contain grease/oil (at least on motorcycles) and they barely contain enough grease/oil to prevent rust
Pennies from outsourced parts go overseas, but the Dollars stay in the USA. And belong to an American owned company. All the money from metric bike and parts sales leave the country.,,
Double post.,,
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Originally Posted By: BigCahuna
All the money from metric bike and parts sales leave the country.,,
Tell that to the American owners of those Dealerships, and their American employees..
All the money from metric bike and parts sales leave the country.,,
Tell that to the American owners of those Dealerships, and their American employees..
More money leaves the country then stays here. It doesn't have to, the buying public make it that way.,,
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