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Discussion Starter #1
Alright, bear with me here, this is far from objective.
A few months ago, I get a zx10. Its great. The bike can do no wrong. Just point and twist the throttle. Bumps dont matter, well there was one bump that mattered, only 1 in my 100 miles weekend ride. First time on i got both tires scrubbed to the edge.
So I take it to track, and wreck it. Look at everything.. Suspension doesnt seem to be damaged. Forks look streight.
So I fix it.. Takes a little time. Then I realize I got learn how to ride all over again. Some how my body got stuck in making all the mistakes it didnt earlier.
So I go on the quest of relearning, but its harder. The bike just doesnt inspire confidence. I thought it was a mental thing, untill two friends in a row told me its "Stiffer than morning wood"
Ok lets go after the settings (they were still on default, since I'm 150lbs) Ended up backing the forks 7 clicks. 5 on rebound. Could use more. The rear is backed off half a turn from full soft. Its better, but small bumps in corners still upset the chassis, mainly from the rear wheel. So WTF?
Did I used to go faster just by courage alone. Did it always upset, and I just didnt back off? Or could the wreck damage the suspension so it cannot react as fast? I'm confused.
I dont know if this has anything to do with it or not. I look at the forks the other day, and see that ring of oil and dirt around the lower legs. Like they are just barely starting to leak. Or maybe picked up oil elsewhere. So I wipe it all off, and with the front brake down, compress the forks pretty good. Lo and behold, there is a barely visible ring of oil on the lower tube, where the seal changed direction... You can barely tell, its just a tad darker than the already dark tubes.
I plan on rebuilding the forks, and shock this winter. I can check everything then. What should I look for? any of this sound familuar?

Is it all in my head?
 

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Discussion Starter #2
Well its not all in my head. Borrowed a budies 600RR. he has it set very very wierd. Preload to the max, and compression and rebound pretty soft. That and he weighs like 130.. even tho the settings were stiff as hell, the bike didnt budge as mine does. It just bounced about, where as mine kind of bucks, at lower frequency but greater amplitude. Either way I was immidiatly going faster on his bike, not being familuar with it, than I was on mine.

Of course the fact that throttle control means a great deal less on a 600 had something to do with it.
 

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Hi jrog24-

Have you seen some of Vash's riding pictures that he has posted from track days? He knows how to ride a 1000cc motorcycle plenty well, I'm thinking we need to concentrate on the original suspension questions...

~ Blue Jays ~
 

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jrog24 said:
Should have gotten a 600 Vash, 1k to much for you.
Ya dude, i dont think i've ever seen vash post a question, hes the one i rely on to answer mine :S
 

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One thing you probably know is that oil rings on the fork legs tells you one or both fork seals are shot. After that prang on the circuit one can pretty well suspect it.

Not that it is going to solve all your problems, still one answer.
 

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But I bet Vash will admit he may want to trade in his liter for a middleweight.

Don't you have warranty Vash, wouldn't the dealer do a free check up for you?
 

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What up, V? Let's start at the beginning...Kawasaki suspension is overly stiff, with not enough low-speed damping, too much high-speed damping, and woefully inadequate rebound. Always have been. They just changed suspension suppliers from KYB to Showa, which should help future buyers, but doesn't do anything for us...

Change the fork oil, and replace the seals. As far as the rear shock goes, if you're going to take the time to remove it, you should replace it with a quality piece.

Check out http://zx-12r.org/phpBB2/viewforum.php?f=6&sid=1cded8f0134a0ad6af93a5659559307e
for ZX10 tech............
 

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Discussion Starter #10
jrog24 said:
Should have gotten a 600 Vash, 1k to much for you.
Actually, yes you are right. A liter is a raging beast, that I constantly have to fight to control. And while my throttle hand is getting pretty good, It still takes a considerably ammount of attention to keep the rear tire from sliding out in a corner. Thats what I loved in a 600, is that I have more of my attention to spend on the road, since you can be as ham fisted with the gas as you want. That and the front wheel doesnt try to kiss the sky on every corner exit... Plus they are so much fun to hunt thru the tranny for power. If I could I'd trade my bike for an RR right now. But I cant, so I'm just going to have to wait and buy one...

Rundog:
My suspension is showa. What really puzzles me, is that I did not notice any of those problem prior to my wreck. I dont know if they didnt exist then, or if I simply didnt care, becouse I felt invincible (and coming from a much worse suspended bike).
Do you think the fork oil could have gotten contaminated due to the (possibly) leaking seal? Or is it that the damage seal created more stiction (is that a word?)? As for replacing the rear shock, I'll consider it, but it will most likely be out of my price range, as I'm starting to realize the buity of dampers. A decent shock will run about $1k right?

Z fanatic:
I dont trust the dealer farther than I can spit. They got some highschool kids working in the shop. I'd much rather do my own work, learn all about suspensions. After all, how hard can it be? (Famous last words)

Bluey:
The leak is real small. If the forks were not coated in that black stuff (silicon nitrate?) and were just silver, I wouldnt not have seen it. The ring is not even left every time I bounce the forks, just sometime, and its really really light. There is never a full drop of liquid. The pads are fine, and the bike stops very very well.

Smitty:
There are a number of things that could've coused the to go. The "prang", being bottomed out in my truck for several days, my recent fascination with wheelies, and a few BP ones that didnt come down all that smoothly. Who knows. I dont mind replacing the seals, But could they have anything to do with my suspension feeling stiffer?
 

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Showa - lucky you... It is entirely possible that having the forks compressed while the bike was in the truck would have caused a small amount of fluid to be forced past the seals without actually damaging them Same for hard landings from wheelies, although your steering head bearings will get enough of that pretty soon. I'd clean the forks, take a 10 mile ride and if there wasn't evidence of a continual leak, I wouldn't worry. A very small amount may still be trapped between the dust seal & the fork, which may take a little to work its way out, and which may show up on the slider.
If after a long ride the total loss including what you've already cleaned off seems to be a teaspoonful or less, dont worry...

Here are some settings from Sport Rider for a 10. I don't think much of their mag, but at least it's a starting point.....

Front - Preload: 5 lines showing
Rebound: 4 from full stiff
Compression: 7 from full stiff

Rear - Preload: 14mm fo thread showing from top of collar
Rebound: 1.5 turns out from full
Compression 3.5 turns out from full


These settings sound like they'd be better for the track than the street.

Seems unlikely that the rear shock would be damaged by a crash, but there is a slim possibility that the bearings in the rear suspension could have been. You can disconnect the rear shock from the linkage, and move the linkage through its range by hand to check for tightness or binding.....
.
 

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Discussion Starter #12
You seem to be right on with the leaking past the seals idea. The total ammount lost after a ride is maybe 1% of a tea spoon. Just enough so that if you are really really paranoid, you'll notice it, after looking for a long time.

I'm not sure I completely follow your direction for checking the rear bearings. Disconect the shock and move the swing arm up and down? How do I support the bike?

My current settings are much much softer than what you have here. I started by setting them to the halfway point, and ended up backing off 5-7 clicks to the soft side.
The front soaks bumps fine now, without upsetting the chassis, but it does tend to dive and rise, abit floaty like. I would have thought it was becouse it was too soft, but any stiffer and the bumps get transfered harshly, upsetting the chassis, and stealing tracktion.
The rear is almost full soft on both compression and rebound, but bumps still feel very very stiff.
 

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Vash said:

My current settings are much much softer than what you have here. I started by setting them to the halfway point, and ended up backing off 5-7 clicks to the soft side.
The front soaks bumps fine now, without upsetting the chassis, but it does tend to dive and rise, abit floaty like. I would have thought it was becouse it was too soft, but any stiffer and the bumps get transfered harshly, upsetting the chassis, and stealing tracktion.
The rear is almost full soft on both compression and rebound, but bumps still feel very very stiff.
Let me see if I can add to the confusion (hope not Vash...)

When you say you backed off 5-7 clicks, are you talking about the preload (the hexagonal tube at the top of the forks with lines on the sides) or the screwdriver fittings at the top and bottom of the fork ( damping settings ).

And on the rear you said you are on almost full soft for damping, but what about your preload?

I would start with proper static sag front and rear (about 1-1/4 to 1-1/2 inch front and rear). The begin using the damping settings suggested by Sportrider (previously quoted by another poster). All this and about 32-35 psi in the tires, then ride. See how it feels.

I'm gonna pm you my real e-mail address so I can send you some suspension troubleshooting documents. Maybe someday I'll post them here.

Stock suspension components are probably not up to the riding it sounds like you do. I think at your weight, the springs are probably up to the task, but generally, valving is not very good for serious riding. You can check with RaceTech during the off season and look into the Gold Valve kit and the Fork rebound gold valve, but I don't see anything for your back end. The page says to call them.

I use Racetech springs and valving in my FZR and it made a huge difference and then just got better when I added the Fox Racing shock. The YZF is going to have front and rear done by racetech (actually sending them an extra shock I have this weekend so I should have it back next week).

Hopefully some of this helps.
 

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REVALVE AND RESPRING IT

Vash its a few bucks but revalving it and respringing it with racetech would be great improvement. My buddy and I did both our motocross bikes front and rear ourselves. Never would I ride a stock suspension bike again. I'm definately going to do my street bike next. The instructions and support from racetech made it pretty easy.
 

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Discussion Starter #15
Thanks guys.
DanQ:
I never touched the preloads. Its my understanding that the bikes are designed with a 150lbs rider in mind, which happens to fit me. In addition, from everything I can tell, them main reason to adjust static sag, is to insure you have enough suspension travel up and down. I'll set the static sag this weekend, I wonder if I'll have to touch the adjusters.
I adjusted mainly the compression (bottom of the fork), and sort of guessed on the rebound. Ended up keeping the rebound 2 clicks stiffer than the compression. The rear has no clicks, so I'm going by turns.
I also wonder how much of this could be attributed to lack of a steering damper? When the suspension was stiffer, the bars had a bad tendancy to wiggle once a critical lean angle was reached (on not quiet track worthy pavement).

97:
If you dont mind me asking, how much money are we talking about here? Or can I possibly revalve my own forks while I got them apart?
Is it common not to be able to rebuild the rear shock?

Oh, and the last stupid question, what color is suspension oil? When some of it leaks out (either on the forks, or by the adjusters on the rear shock) is seems almost black. I always thought it was going to be a light amber color, maybe its time to change it? 6-10mo on the bike...
 

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Vash said:
Thanks guys.
DanQ:
I never touched the preloads. Its my understanding that the bikes are designed with a 150lbs rider in mind, which happens to fit me. In addition, from everything I can tell, them main reason to adjust static sag, is to insure you have enough suspension travel up and down. I'll set the static sag this weekend, I wonder if I'll have to touch the adjusters.
I adjusted mainly the compression (bottom of the fork), and sort of guessed on the rebound. Ended up keeping the rebound 2 clicks stiffer than the compression. The rear has no clicks, so I'm going by turns.
I also wonder how much of this could be attributed to lack of a steering damper? When the suspension was stiffer, the bars had a bad tendancy to wiggle once a critical lean angle was reached (on not quiet track worthy pavement).

97:
If you dont mind me asking, how much money are we talking about here? Or can I possibly revalve my own forks while I got them apart?
Is it common not to be able to rebuild the rear shock?

Oh, and the last stupid question, what color is suspension oil? When some of it leaks out (either on the forks, or by the adjusters on the rear shock) is seems almost black. I always thought it was going to be a light amber color, maybe its time to change it? 6-10mo on the bike...
you only need to mess with preload to set the sag 25mm for a track bike and 30mm if you spend all your time on the street, if your bike wallows a bit in back, I believe you said it bucked a little, that isn't nessesarlay a bad thing, but you can reduce the tendency to wallow by increasing the rebound a little or reducing compression, fiddle with it a little til it feels good, start at the softest settings and work your way up from there, you'll find the magic number and then your bike will feel like it's part of your body.
If the fork oil is black then it needs to be changed, it is generally a good idea to change fork fluids every two years depending on how you ride, fork oil should be almost clear light amber colored, if it is dark then there is lost of contamination in it and it's time to clean it out.:2cents:

almost forgot, the stiffer the suspention the faster you can go, stiff suspentions might not be so good for the street, so find a compromise if you can't tolerate the beating you get on your commute.:2cents:
 

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mstrand_68 said:
Maxima Racing fork fluid is blue, along with some others. That's all we run at our shop unless customer specified.
jap bikes don't run that stuff from the factory, the garbage that come in most motorcycles is kinda like fish oil. and you should still be able see through racing oil. the stuff i put in my last bike when i installed the gold valve stacks was blue, but i could still see through it.:2cents:
 

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You can see through it, it's "clear blue" at 125-150 I guess I should of said. We have some Spectro thats amber, but its 10w. It's more for dirt bikes or older cruisers. I wouldn't put the amber crap in anything I own. But then again there might be a really good fork oil that is amber, I haven't seen any. Anybody?
 

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Discussion Starter #20
Fatman:
How much of a difference did you notice from the gold valves? also how did you pick the right set?

Since I'm rebuilding the forks, it seems like a good time for a re-valve, if its worth it. Race-techs site does no specify kits by bike model, so it confused the crap out of me
 
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