C10 fork oil measure comparisons

[Mercer]

For reference on C10 fork oil measures recently:

On C10 early forks normal oil level is approximately 14 inches at full extension per factory. This results in a 6.5 inch measure compressed approximately.

The following is a result of other comparisons:

On same fork 13" extended is to 6" compressed.
12.5" extended is to 5.5" compressed for further comparison.

The more oil in fork to a max of 5.12" (from Race Tech tuning manual) would control last 1/3 of fork travel and limit brake dive according to Race Tech. My choice was to use 5.5" as my limit as I did not want to shorten fork travel by hydro locking fork in compression too early.

I am currently using 5.5 compressed/12.5 extended to control brake dive as fully as practical.  Air assist is disabled by plug of balance holes. I am very happy with the current result.

This measure point might not be for everyone as brake dive preferences are subjective as is suspension feel. But for my road conditions I like it very much.

 

[boomer]

I've just ordered RaceTech emulators for my 89. How didja plug the balance pipe holes?
Mine will be used with Sonic 1.2kg springs and I need to figure out what fork oil weight and level to use for my weight. Like you I'm expecting to have to do a bit of experimentation.

 

[MAN OF BLUES]

I've just ordered RaceTech emulators for my 89. How didja plug the balance pipe holes?
Mine will be used with Sonic 1.2kg springs and I need to figure out what fork oil weight and level to use for my weight. Like you I'm expecting to have to do a bit of experimentation.

EASIEST way is to cut a strip of innertube (bicycle or m/c) about 1/2"-3/4" wide, and long enough to do a single wrap on the tube, (or even a strip of tube patching material) and apply a radiator clamp to compress it... easily removed for pulling the forks, or e-installing... just center it over each hole in each tube.
I've used this when doing Progressive springs from Murph.

 

[connie_rider]

Lee, reading this discussion and your C-14 Shock discussions it sounds like you have the front end set up way stiff and the rear soft. Have you set the spring sag with you on the bike?

Ride safe, Ted

 

[Mercer]

Connie Rider (Ted) and myself in discussion, are both concerned about the lack of linearity in my measurement comparisons. Truthfully can not account for it though it was noticed while making measures. One would think all measures should be linear as oil is added to fork extended and/or compressed. This because oil is added to fork is above emulator level. Would suggest for moment my figures be questioned due to above.

I do intend to repeat measurements in time. As my C10 is performing admirably suspension wise, will not be using it for a remeasure of oil level values. I usually commute on it daily. However, do have an extra set of forks. So as time allows will repeat the measurement comparisons posting results here.

 

[Mercer]

Ditto for Man of Blues's recommendation. That was exactly the way I did it as my o-rings on crossover were leaking after fork rebuild.

 

[Mercer]

Ted,

I was using 3 clicks from softest position on C14 rear shock. My C10 front forks did "feel" somewhat stiff. But moving to 4 clicks from softest setting on rear seemed to balance bike front to back softing the front "feel". Know this is subjective but I am very pleased with this set up now. The front spring sag is 19mm riderless, bike off stands, with 14mm more with rider on board for a total sag of 33mm.

 

[willyp]

If they aren't leaking is there any reason to remove the balance tube?

 

[MAN OF BLUES]

If they aren't leaking is there any reason to remove the balance tube?

only if they have been updated to a new construction, such as Progressive Springs, or other internal parts, which takes the necessity of adding air, away from the forks from that point on... that, and the fact it's just another part/seal/thing to **** with in the future when doing services. so, no, if they ain't leaking it's all cool... no different than people removing the reed valves from the valve cover, and spending time/money/risk of not doing it "correctly"/etc., for no benefit. :rotflmao: :rotflmao: :rotflmao: :rotflmao:

funny you should mention it tho,
I have a set of old Ninja Forks, with the "anti-dive-braking feedback system", sitting in the same box i got them in when I bought them, a decade ago... yet to be installed, as I would need to change my braking system hoses to accommodate them.. meh, maybe someday... :rotflmao: :rotflmao: that bike is in the garage, covered, sitting... an likely my grandson will be the one that uses all my "extra parts" collection to resurrect my old bikes, when he inherits them, and all my guns... in 10 more years from now.

 

[Mercer]

Please note:

In tuning my forks for brake dive I was getting erroneous and unreliable measurement readings for my early model fork per the factory's fork extended recommendations. This perplexed me and caused considerable consternation on my part. This observation started an investigation over a few days on fork measuring and measurements of the C10.

I repeated my calculations of extended/compressed measurement comparisons and corrected my first post of this string.

After repeated tests I believe the extended test and recommendation in factory manual for early an model fork to be unreliable. If I were changing oil or tuning  fork oil I would use the 6.5 measure compressed as my reference.

If I were using other fork oil measures I would only measure from the fork compressed position.
I believe others have debated this before. But after multiple tests cycling oil through forks I have concluded extended measures to be unreliable and the more viscous the oil and colder the temperatures, the more that unreliability is evident.

What I found is in using sets of modified 1987 and stock "1992" (corrected as typo) (Connie Rider knew better) forks as test beds, that oil is somehow displaced in such a way that even after sitting overnight 330 units of oil will measure differently from one fork leg to the other on the same fork in the extended position.  As well if you withdraw this oil and replace it, the values on depth measure will change erroneously. In some cases dramatically.

This makes tuning difficult obviously. This was never the case in testing forks compressed.

I know I am no expert on this subject. Others here certainly have more experience with the C10. These are just my recent observations while tuning my front suspension per Race Tech's manual and other references.

My opinions are based only on direct observation, measurements, and comparisons. Hopefully my measurement findings in first post of this string might make fork tuning easier for others at my newbie to the C10 skill level.

Special thanks to others corresponding and posting on this subject across this board and others. Got ta luv the COG resources!

 

[MAN OF BLUES]

thank you for the documentation of what you found.

I will say, you did have variables induced into your experimentation, that cannot be construed as conducive for viability of statements, when someone is simply doing a fluid change on an UN-MODIFED, or "as delivered from factory/OEM" STOCK fork.

with regards to fluid quantities, and inconsistency you state, as outcomes, can only be explained by the modified/ or aftermarket parts interchange, and the way those parts functioned, in lieu of OEM configuration.

I do again thank you for your experiments, but I still don't want someone that has never worked on these bikes, to show up here, and "use this as gospel" for a simple oil replacement on an OEM fork.
Over 15 years, I have seen a lot of mistakes, and heard a lot of crying about blowing out seals...  I have NEVER heard of a mishap, when the OEM forks, were serviced per the correct methods,based on model year, and using OEM parts.

glad to hear the mods you did seem to be working, please do report back, and tell us after 20k miles, if they are still happy.

ride safe, :motonoises: :great: :great:

 

[Mercer]

In reviewing my comments based on MOB surmise, noticed a typo that Connie Rider had pointed out and I had missed in his e-mail on it. 2000 should have read 1992. Who knows why 65 yr old brains and fingers short! It is corrected now above.

 

[MAN OF BLUES]

In reviewing my comments based on MOB surmise, noticed a typo that Connie Rider had pointed out and I had missed in his e-mail on it. 2000 should have read 1992. Who knows why 65 yr old brains and fingers short! It is corrected now above.

so even tho you corrected the model years, you were comparing two sets of forks, that are identical in construction.. i.e., pre 94 change over. You noted "erroneous results" during the process...which should not occur: but, even then No big deal,(as I personally didn't go thru the process, remove every part, clean them all meticulously, re-assemble and document it in my manner..); but again, I don't want "drop in" people to surmise all of this as gospel on fork oil levels, and still ask folks to use the book, and follow procedure, including recommended levels per-se.

 

[Mercer]

The following is said tongue in cheek. It is hard to inflict a tone in writing sometimes. Oft times English words get viewed as gears to grind. Which these words are not! Please read this following as a comical play with words. But do hope as well my meaning is taken in the spirit of perfecting the steed we ride. There have been a few here of late as heavy (lbs) as myself trying to tame their C10 suspension. I have been posting, not scripture to follow as gospel, but some information that might be helpful to those and perhaps maybe some others as well.

Was not me saying, "use this as gospel"?  I have made no gospel statements. Did offer up personal insight into discoveries while in the process of tuning a C10 for my weight and road conditions here in Louisiana. The reasons why I did not use plug and play offered here. Also made it clear the level of my expertise with a C10 before any incarnation on this site. Also tried hard to be accurate in my findings and when was not, tried to discover and entertain why thought it was not possible.

What gospel is being referenced? The Kawasaki manual? Race Tech's treatises on suspension tuning? Some other authoritative sources? I have read these gospels, some other holy books too. But as a Pagan the lord blessed me with the privilege of accepting only dogma that my mind and heart does see and touch. The lord saw fit to show a 295 lb Pagan how to modify from the gospel's word my stock suspension to accommodate my weight and the roads I drive on. He also taught me it is not the words in the gospel but meaning of the words. Taught that a 295 lb rider needs to alter his suspension differently than a 145lb rider for maximum benefit.

To my understanding this is a place of discovery, sharing, and discussion. I have shared discoveries and opinions. I have corrected my errors when others offered insight or caught my mistake. If there is disagreement here I do not have a problem with it.

Mainly because I am learning a lot here, discovering some more, and am having a tremendous amount of pleasure in the pursuit of riding, improving, sharing knowledge of, and the loving of, a C10. Kind of notice others have been doing it here too, for a very long time.

Gospel? Kind of hard to find such on this site, even with the search tab. At 20k more miles do not think one will find any gospel here from me even then.

Again all said as light hearted as possible for all our mutual amusements and benefit. I can not begin to express how many ways this site has allowed this Pagan to bring a worthy steed from the last century into this century. Quite effectively too! Thanks again to all who make this site great.

 

[connie_rider]

Well said.

Ride safe, Ted  {another COG Pagan}..

 

[MAN OF BLUES]

works for me  :great: :great:

I cut the soles off all my shoes, and now I sit up in a tree, in the woods, learning to play the flute..... modern day Druid I am... :rotflmao: :rotflmao: :great: :great: :great:

 

[Mercer]

Off topic perhaps, but seems Druids proceeded Pagans by many hundreds if not thousands of years.  Nice picture! The beards if real are certainly testament. Might have to differ to some that ole time pregospel knowledge here. When I alluded to very long time everyone including me had no idea perhaps! Glad for the diversity, glad for the sharing, thanks again all.