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ass hole extaordinaire
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Discussion Starter #1
what is the max pressure that i can run in my 86 forks?

12.5 oz of oil is whats needed to fill up each fork right?

and last is this oil compatible with our forks?

 

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ass hole extaordinaire
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Discussion Starter #3
Oh good, an actual motorcycle question!

I think the correct oil amount is 10.9 ounces., the forks can go as high as 7 psi and the oil you show would be fine.
lol :beerchug: actually i posted all these questions in my crash thread but no one answered them so i had to start a new thread :hitanykey

then where did i get 12.5 ounces from i remember reading it some where and i could have swore i saw 40 psi was the max on the forks
 

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lol :beerchug: actually i posted all these questions in my crash thread but no one answered them so i had to start a new thread :hitanykey

then where did i get 12.5 ounces from i remember reading it some where and i could have swore i saw 40 psi was the max on the forks
Well I did say "I think"....meaning I could be wrong....

But when I did my forks I put in 11oz. Perhaps 12.5 is if they are brand new and totally dry?

40 sounds high for the forks.

See, this is why you are supposed to have a shop manual...;)

From my write up in the Verses (you look there?):

"I used a measuring cup to meter out, as close as I could tell, 10.8 oz (320mL) of 15w Bel-Ray fork oil. used a piece of tape to mark the cup so I would be sure each leg got the same amount of oil. It was roughly at the 11oz line. Used a small funnel to fill each leg"
 

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ass hole extaordinaire
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Discussion Starter #5
yea i disassembled them and let them drain for a day
so i think i will be ok i kinda asked after i put the oil in ;)
 

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Its the shocks that can be pumped up some....7lbs is correct....use a hand pump....and you dont "need" to have air in them...actually, the 7 lbs is barely noticible....guess thats why they stopped doin it....besides, wouldnt the air pressure cause the oil to foam more ? I never ran air in mine.
 

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ass hole extaordinaire
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Discussion Starter #7
two votes for 7lbs so i better back off the psi about 23 lbs since i am at 30 lbs

but it sure rides nice with all that air maybe there is a stiff springer in my future ;)
 

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lol :beerchug: actually i posted all these questions in my crash thread but no one answered them so i had to start a new thread :hitanykey

then where did i get 12.5 ounces from i remember reading it some where and i could have swore i saw 40 psi was the max on the forks
I believe it was the rear shocks that can take the higher PSI, though certainly not 40. The pressure of the rear goes off of your weight per Roach's video, I forget what the manual says.

Rear Shock Oil Change

As for the forks, there is no mention in his video itself about the PSI used, but its noted in the comments that 7psi is that max you want. (And only then if you are of a heavier build)
Fork Rebuild Video
 

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Its the shocks that can be pumped up some....7lbs is correct....use a hand pump....and you dont "need" to have air in them...actually, the 7 lbs is barely noticible....guess thats why they stopped doin it....besides, wouldnt the air pressure cause the oil to foam more ? I never ran air in mine.
More pressure would actualy reduce the amount of foaming...(which are bubbles created in the oil). The extra pressure makes it harder for bubbles to form.

Think about a soda bottle, it bubbles up after you remove the cap and release the pressure.

Many have installed heavier springs, putting in the Progressive springs is like the number 3 or 4 mod reccomended.

You should read the Verses again...;)


I ran 14 psi in the forks of my race bike and didn't have any problems. Keep in mind the 7psi max listed listed by Kawasaki might just be like the 5 pounds max for the luggage rack....more of a liability figure than a tested one.;)
 

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ass hole extaordinaire
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Discussion Starter #10
More pressure would actualy reduce the amount of foaming...(which are bubbles created in the oil). The extra pressure makes it harder for bubbles to form.

Think about a soda bottle, it bubbles up after you remove the cap and release the pressure.

Many have installed heavier springs, putting in the Progressive springs is like the number 3 or 4 mod recommended.

You should read the Verses again...;)


I ran 14 psi in the forks of my race bike and didn't have any problems. Keep in mind the 7psi max listed listed by Kawasaki might just be like the 5 pounds max for the luggage rack....more of a liability figure than a tested one.;)
thats kinda what i figured i think i will run about 12 to 15 and see what happens i have leak proof seals so if they leak air i know who to blame :beerchug:
 

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I just took a pair of springs offa some Sportster shocks and put em on the outside like helper springs (perfect length, btw)....covered with rubber boots....less than half the cost of new internal springs too. And even with new seals, mine never held air....

More pressure would actualy reduce the amount of foaming...(which are bubbles created in the oil). The extra pressure makes it harder for bubbles to form.
Thats why I added the question mark. From my MX racing days, I remember fork oil foaming was a big issue...but that was 38 yrs ago...I cant remember the details !....lol....
 

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Another aspect here which I didn't mention is adding pressure inside a normal sliding front fork can increase stiction. Fork seals aren't made to be "air tight" but are because the way they have to be made anyway.

The seal is basically a flexible squeegee that's angled DOWN the fork tube. Internal air pressure would "push" the "blade" against the inner tube harder if increased.

Even if your not running any pressure in your fork, when it compresses it would be increasing the air pressure inside the fork. Charging the inside of the fork with more air still means internal pressure will rise as the fork compresses.

The seal then would be pushed against the inner fork even harder if extra pressure is added. I'm not sure how much pressure the seal itself can handle, but any increase will do two things:

1- Increase wear on the seal itself.
2- Increase stiction.

Stiction exists in all forks. It's not a constant "force" but a threshold force that must be overcome to get the fork to begin movement. The less stiction the fork has the more fluid its movement.

Thus, adding too much air may make the forks less responsive to "small" movements like expansion joints on the road. (Besides increasing wear to the seals)
 

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Old Twistie Sticks Rider
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Not the same animal but Showa forks... I only run 5 psi in my Sportster shocks w/progressive springs and I weigh 225#... I feel sure though the Showa shocks were probably set up much different for different bikes... I'm just sayin this because I would not go over the recommended 7 psi much if any... I'm thinkin as KM stated that it very well would cause early seal wear & replacement...JMO...
Have a good one...Old Dog...
 

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ass hole extaordinaire
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Discussion Starter #15
all good points brothers as of right now i havent aired them back up i just wanted to take a bit of um action out of the front end because on hard braking it feels like i am about to endo the way the forks retract
 

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all good points brothers as of right now i havent aired them back up i just wanted to take a bit of um action out of the front end because on hard braking it feels like i am about to endo the way the forks retract
You could increase the preload by installing longer spacers or adding about an inch and half to the stock ones. A stack of washers on top of the stock spacer does the trick too.
 

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Linkmeister Supreme
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Rear shocks usable pressure is up to 43 psi.
Recommended pressure is 10% of rider(s) and luggage weight to be carried.
Max recommended weight to be carried is about 400 pounds, (397 precisely).
 

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ass hole extaordinaire
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Discussion Starter #19
You could increase the preload by installing longer spacers or adding about an inch and half to the stock ones. A stack of washers on top of the stock spacer does the trick too.
ok you lost me here km

Rear shocks usable pressure is up to 43 psi.
Recommended pressure is 10% of rider(s) and luggage weight to be carried.
Max recommended weight to be carried is about 400 pounds, (397 precisely).
i have harley shocks on the rear
 

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ok you lost me here km
"Pre-Load" means exactly that, you are pre loading the springs while they are at rest by making them compress a little more. This is done by putting spacers on top of the springs so when the top plugs are installed the spring is slightly more compressed. This "loads" the spring making it slower to react.

On rear shocks this is usually done with a ramped collar that compresses the spring more when turned.

On the front fork this is done by lengthening the spacer that sits on top of the spring.

Get it?
 
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