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Discussion Starter · #1 ·
My last post about using Dave Moss Tuning as a guide for adjusting suspension disapeared, not sure why. Anyways.... I wanted to getvthe most out of this stock suspension without springing for a 500-1000 dollar upgrade kit. I learned alot about suspension settings from Dave Moss Tuning and set to work doing what I could. His recommended settings for regular use are 15-25mm Static Sag in the front and 30-33% fork travel as the setting for total sag with rider. For us thats 34-38mm total sag because our ACTUAL fork travel on the Z650 is only 115 mm. For the rear he recommends 10-15mm static sag and and for us 39-43 mm of total sag with rider. I was able to get these dialed in using a combination of rear preload and fork height adjustment but there is a bottom out problem because the suspension is "soft". What I came to realize is that a common misconception for our bikes is that the spring is at fault. No. The truth is (in my case and utilizing the tools I got from weeks of research) that our springs are fine. Our FLUID is to thin. 10 weight fork oil is not satisfactory for anyone over 140 pounds. At 180 no wonder I was bottoming under hard breaking. Doing the math using our actual fork travel and geometry relative to the triple tree clamp, I also found that the preload spacer is applying too much preload. In order to get a perfect setup geometrically one would have to move the forks in the triple tree clamps way too high or run out of room moving it down low. So..... Heres what I did.

I used a 1 inch diameter PVC as a replacement preload spacer. I cut it 10mm shorter than the stock spacer (to remove some preload) and replaced it while also changing to 15 wt fork oil.

WOW.

No more bouncing around up front. Not only that, I was able to dial in those "perfect" settings provided by Dave Moss. The only other thing I did was move the forks down in the clamps by 2mm (stock is 6, so mine are at 4) to fine tune the geometry and get me RIGHT in the middle of his specs.

What did it cost?

1.30 PVC
15.95 Fork oil
Time and effort.

Let me know if you have any questions, just thought I'd let everyone know we can make our suspensions better on the cheap. I plan on buying a real upgrade kit later but I took this as a personal challenge to get the most out of what kawasaki gave us!
 

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I stumbled on Dave Moss while researching which bike(s) I was interested in - mine's brand new so the thought of pulling the caps on a brand new bike and draining the oil at 20 miles on the odometer is troubling, but definitely doable when I'm doing my 500 mile oil change. If you don't mind answering, how tall are you and what's your weight? I'm 5'10" 200lbs right now (hoping to drop a few more, goal is to get to 190lbs)... wondering if your setup would work for me.

Also, did you adjust your rear spring or is it at the factory setting?
 

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Discussion Starter · #3 ·
I stumbled on Dave Moss while researching which bike(s) I was interested in - mine's brand new so the thought of pulling the caps on a brand new bike and draining the oil at 20 miles on the odometer is troubling, but definitely doable when I'm doing my 500 mile oil change. If you don't mind answering, how tall are you and what's your weight? I'm 5'10" 200lbs right now (hoping to drop a few more, goal is to get to 190lbs)... wondering if your setup would work for me.

Also, did you adjust your rear spring or is it at the factory setting?
Hey yeah Im 5' 6" and 185. I think you could go with 15wt or 20 wt fork oil. I also think doing your spacers 10mm shorter per Dave Moss recommendation would be just fine. Because you are taller you probably sit more upright than I do which would center your weight closer to the seat as opposed to where I sit leaning further onto the bars. So I think you could leave the fork height at the stock 6mm. I believe I am 1 click stiffer in the rear at 185 its perfect for me.
 

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I emailed Dave Moss to get some tips and he was kind enough to respond.
The first thing he suggested was to change up the fork oil to 20w, which I ordered and is on the way.
I'm 235lbs, so the next thing he said was that I will overload the rear shock as I gain experience (I just got my permit) and to look at replacing the spring at the very least.
I've been tinkering with getting that sweet spot with the rear (I will wait to change out the fork oil before doing anything in the front)
My questions to you: Isn't the spacer in our forks made of metal? You sure pvc is ok? I've seen the vid where Dave moss does that with the mt-07 and shortens the spacer to get better ride, but they used steel pipe.
Next question: I changed the preload and I turned downwards but I feel like my free sag increased. Unless I'm measuring wrong, isn't the opposite supposed to happen?
I'm looking to get that sweet spot as well, the sag with me on it is 32mm and the free sag is 18mm. That adds up to a 50mm, which is 50/130 or 38%. Maybe I'll just keep preloading it. I'm not even sure where it's at.
Finally, our rear is kinda weak, and suggestions on replacing it with a stiffer spring?
 

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I emailed Dave Moss to get some tips and he was kind enough to respond.
The first thing he suggested was to change up the fork oil to 20w, which I ordered and is on the way.
I'm 235lbs, so the next thing he said was that I will overload the rear shock as I gain experience (I just got my permit) and to look at replacing the spring at the very least.
I've been tinkering with getting that sweet spot with the rear (I will wait to change out the fork oil before doing anything in the front)
My questions to you: Isn't the spacer in our forks made of metal? You sure pvc is ok? I've seen the vid where Dave moss does that with the mt-07 and shortens the spacer to get better ride, but they used steel pipe.
Next question: I changed the preload and I turned downwards but I feel like my free sag increased. Unless I'm measuring wrong, isn't the opposite supposed to happen?
I'm looking to get that sweet spot as well, the sag with me on it is 32mm and the free sag is 18mm. That adds up to a 50mm, which is 50/130 or 38%. Maybe I'll just keep preloading it. I'm not even sure where it's at.
Finally, our rear is kinda weak, and suggestions on replacing it with a stiffer spring?
I just measured again with the help of my son, i must have measured wrong, rider sag was over 40mm. I added some more preload now, and I got free sag at 7mm and rider sag at 37mm, with a grand total of 44mm. I will have to live with this at my current weight and with the stock spring. I'll check my numbers again when a buddy comes over. I keep getting different results.
 
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