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Race tech and Paul Thede and Lee Parks are are famous and well established people in the motorcycle industry.
 

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I can see why, it takes a real pro to break down suspensions to a level that anyone can understand.
 

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The black collar under the spring (with the drilled holes) is the preload collar. Technically, there is also one at the top of the spring. The red knob is rebound and the black knob on the reservoir is compression. With that in mind, I recommend doing the following...in this exact order.

1. Get a helper or two to set rear sag and put on all of your riding gear. Yes, even the helmet.
2. Unload the suspension (either have your friends lift the rear of the bike or pivot it up with the sidestand). Make a reference measurement to determine your unloaded length. I recommend using a point on the tail section in line with the axle and a corresponding point on the axle/swingarm. Write this measurement down (I prefer to work in metric, but English is OK if you're good with reading the tape and converting). Let's call it X right now.
3. Sit on the bike with your feet on the pegs. This is where friend #1 comes in. Sit like you would normally sit.
4. Have friend #2 slowly lift the tail section up and gently let it lower under your weight. Re-measure the distance between the same two points. Record this as X1.
5. Have friend #2 slowly push down on the tail section and let it gently return. Re-measure the distance between the same two points. Record this as X2.
6. Average X1 and X2; call it X3. These numbers shouldn't be drastically different. If they are, take your measurements again. The difference between X1 and X2 should be a few mm and no more.
7. Time for some arithmetic. X-X3=rider sag. Shoot for ~30 mm / 1.181". Add preload to reduce sag and remove to increase. The leverage ratio of the stock linkage and swingarm is significant.
8. Once you get 30 mm, I recommend setting the front sag. The process is identical, but your X1 and X2 will be further apart due to seal/bushing stiction. Shoot for around 35 mm to get you started.
9. Now that you've gotten the proper sag, you won't be fiddling much with preload unless you feel the need to change how fast the bike steers. Remember, adding preload doesn't make the spring stiffer. The only way to make a stiffer spring is to alter the material, increase wire diameter, and/or reduce the number of coils.
10. Set rebound on both ends of the bike while in the garage. You're looking for a smooth controlled 'return home' when depressed. A few mm of overshoot is ok, but it should settle back. You don't want either end to rocket back up and top out or oscillate. Conversely, you don't want too slow of a return without overshoot. Getting this right takes experience, a keen eye, and a delicate touch. Once you get both ends right, depress the bike in the middle - left hand on the handlebar, right hand at the seat/tank junction, and right foot on the peg. Push down in the center of the bike, where your body's center of gravity would be. You want both ends of the bike to return at the same speed. Make adjustments as necessary to get this right.
11. For someone new to the world of suspension tuning looking to learn, I recommend setting the compression adjustment to full soft.
12. Go for a ride. Take note of what the bike is doing. Bring the tools you need to make adjustments on the road!
13. Start adding compression. On a Penske, I work in 4 click increments since there is a lot of adjustment. Ride some more.
14. Continue adding compression in 4 click increments until you feel harshness; back off 2 clicks. Ride again and take note of performance. You may need to adjust +/- a click.

Some ROUGH guidelines:
A. If either end of the bike feels nervous, add rebound damping.
B. If either end feels sluggish and doesn't respond fast enough to the road, reduce rebound damping. Same thing if you find the suspension 'packing'. Packing occurs when the a series of bumps causes the suspension to ratchet down with each successive bump. With too much rebound damping, the suspension never fully returns to it's rightful starting point, so travel is limited for the next bump.
C. If you feel the bike is squatting too much, add compression. Just be aware that this will also reduce bump compliance (unless you have a shock with high speed compression adjustment - 8987).
D. If you find you're breaking traction at low wheel speeds, reduce compression.

The static tuning you did in the garage will get you about 80% of the way to a good setup. The remaining 20% takes time with the tools on the side of the road. I make a day of it on personal setups.

Good luck!
http://www.yamahafz09.com/forum/6-f...tilt-tank-need-help-shock-installation-6.html

Awesome thread Nick (Stoltec)!!! Thanks
 

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Sag gauge for one man operation.
Stoltec's info is great, but for those that don't have someone to help with sag measurement you might try something like I use. Land vehicle Vehicle Tire Automotive tire Alloy wheel Auto part Tire Automotive tire Brake Wheel Auto part Vehicle Engine Car Vehicle brake Motor vehicle Vehicle Motorcycle Automotive tire Spoke Tire Automotive tire Auto part Wheel Brake
Any tubing and rod will work for this - you could even roll a paper tube up that would fit in the axle or let whatever rod you use pass through at the top, there is no load on the rod so it could even be a coat hanger straightened out. Use these pics to get the idea and find what you have to work with. To get the all the way out mark pull the bike over on the side stand until the wheel in question is off the ground or very close, put a mark on the rod, now you have a place to measure 30mm or 35mm (or whatever number you are trying for) and make another mark. Put your gear on and you can see the rear gauge in the mirror - the front is right in front of you on the top clamp - as you slowly lower your weight on the bike. If you want to be really 'pure' you can hold on to something for balance and even put your feet on the pegs. I have found I like the rear just little higher and front lower than Stoltecs' numbers, but only by a mm or two. Now if you change something you can get back to a known starting place for ride height.
 

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Sag gauge for one man operation.
Stoltec's info is great, but for those that don't have someone to help with sag measurement you might try something like I use.
Mike, you are doing this to the stock suspension right?
If so and after coming all threads plus the net, it seems that the front and back sag is being adjusted to max (hardest) config. The damping is per taste, here are the settings from 'Adam Waheed Road Test Editor'

2014 Yamaha FZ-09 Comparison - Motorcycle USA
FZ-09 Suspension Settings
Fork
Preload: Full-in (Max)
Rebound: 0.5 (Turns out)
Shock
Preload: Position 7 (Max)
Rebound: 1

Could you let us know what your settings are, and how it improved the riding -thanks.
 

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Each instruction say "now you can set your sag". The measurements are for the current sag so it must be adjusted up or down. Are the adjustments made with the rider on in full gear, with suspension unweighted or on a paddock stand? Having never set sag before, my guess is it does make any difference because only the difference is adjusted.
 

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.... my guess is it does make any difference because only the difference is adjusted.
My distillation to our 9er stock sag configuration (preload) is that it doesn't matter (to dial it in), due to the sub-par OEM suspension (based on the members threads and google searches).
Now, if you go with Stoltech Moto kits, or any other aftermarket suspension.. then you should (have to) setup your bike to the riders complete-fully dressed weight (sag - preload) and damping (by riding style - task).

Well guys.. Suspensions Geeks chime in, we need your input regarding stock and aftermarket sag config.
 

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I have a Penske and I agree. Lets say the measured sag, using the method above, is 34mm and you want 30mm. The preload would be reduced by 4mm. My question above may not be clear. Would there be any difference between: taking the 4mm off of the un-weighted suspension measurement and adjust the preload un-weighted to that reduced number or taking 4mm off of the weighted with the full gear rider measurement and adjusting the preload to that reduced number with the full gear ride on the bike or take a measurement the bike on a paddock stand and adjusting the preload to 4mm less? My guess is no matter how you do the adjustment, the preload will be reduced by 4mm.

Again, none of the instructions explain how to make the adjustment.
 

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Rider: 6'2" 200lbs no gear.
I have a '08 ZX10 shock / stock spring at 180mm (fifth step+ on stock adjuster) [email protected], HS [email protected] 1/2, LS [email protected] 3/4, the front has stock springs w/adjusters all the way down and still ~38mm sag. I have a mix of oil in there to try and guess how heavy it needs to be - 1/4 turn on rebound. I will have a new set of springs in hand tomorrow (.90 from stock .75ish Kg/mm) and will go with Stoltecs recommended 10W when those go in. I will shoot for 30mm sag and raise the tubes in the clamps 8 or 10mm to get the same front tire loading to start.
To get sag numbers; for compression sag I settle my weight slowly on to the bike keeping balance by holding the workbench to keep upright, that is the first number to record, and then leaning forward or back to settle more weight on that end then slowly lean back to riding position, that is the rebound number. These should be very close 2 to 3mm or you most likely are not getting the load / unload right. If you can have a helper pull up - push down to get the load / unload numbers while you sit still that is better way to go. If you can get repeatable numbers doing this two or three times I would bet you are ok.
If you are not changing the sag much on the rear setting sag on the track stand will be close, but remember that the linkage changes the rate with wheel travel like a progressive spring would, so if you can you should check sag the hard way. On the front if you stay with a single rate spring I would change that on the stand and be happy that it is good.
I'll post after the new springs/oil go in.


2/20/14: I had a 30mi. plus ride yesterday with the .90kg springs (from Stoltec/Sonic Springs) and 10W oil in the right side. Nick hit the spring (and recommended the 10W) I needed right on the money. I put a zip tie on the slider so that as you hit bumps during a ride it pushes it down the slider, you can then see what max travel was since you last pushed it back to the top. On 'normal' rides - didn't hit any big pot holes or hop any speed bumps - I would use five inches of travel and get to the soft hydraulic stop at the very end of travel. After the new springs the most I have used is about four inches, that leaves me a little travel for the surprises out there without bottoming out. If noting else get some 10W in the right side, it makes a lot of difference and unless you need a stouter spring may be all you need.

PS: the weight oil in the left side makes no difference so use whatever you think will make things last. I put 30W in just to see if it would provide any damping at all. No change at all in feel pulling the tube in and out by hand, all the oil does on that side is lube the inner and outer tube surfaces so unless you maybe put 120W gear oil or straight STP in there you won't feel it on the road. No, I would not try the 120/STP, if you want the left side to work let Stoltec get his fork kit done and put that in, then you will have dial in adjusters for compression and rebound and no need to change the oil to get there.
 

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I have a Penske and I agree. Lets say the measured sag, using the method above, is 34mm and you want 30mm. The preload would be reduced by 4mm. My question above may not be clear. Would there be any difference between: taking the 4mm off of the un-weighted suspension measurement and adjust the preload un-weighted to that reduced number or taking 4mm off of the weighted with the full gear rider measurement and adjusting the preload to that reduced number with the full gear ride on the bike or take a measurement the bike on a paddock stand and adjusting the preload to 4mm less? My guess is no matter how you do the adjustment, the preload will be reduced by 4mm.

Again, none of the instructions explain how to make the adjustment.
If you were at 34mm and you wanted to be at 30mm then you would need to increase preload not decrease it.

Never set sag while on a paddock stand as you will get incorrect numbers. If you want to be as accurate as possible you would want to be suited up just as you would when you ride.

Terry
 

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Yes....Otherwise she'll feel like a pogo stick.
 

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With max preload frt& rear, I have the frt close to max rbd and rear at max rbd... play with them and see what feels best.
 

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i have a question about if i stiffen the preload fully do i need to adjust the dampening as well?
No, when you add preload you are not stiffening anything. You're just increasing the ride height. The spring is compressed the same amount that it was before. (With a load on on it, of course. If it's topped out it will be compressed more, but that's the only time that's true.)
 

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I'm getting confused on my front forks.

I replaced the springs with .90 and was able to set the sag to 33mm without an issue (everywhere I read said either 30mm or 35mm so I decided to just average tthe two). I also put in 7.5W fork oil on recommendation from Sonic Springs. When the bike is up to speed on a good road, the ride is nice and perfect, but if I get down to city streets, I can literally feel every bump in the handlebars, no matter how small. Small potholes make the front feel like it's bottoming out, and if their is a washboard succession of bumps, it nearly knocks me off the bike.

This happens no matter where I put the rebound adjustment screw on top. If its fully adjusted in, the smaller bumps get absorbed a little better, but bigger bumps are murder. If I adjust it all the way out, bigger bumps are little better, but the front is bouncing all over the place. I've tried adjusting it 1/4 turns at a time and riding the same road, and nothing feels good. Is this indicative of a preload problem? Do I need heavier fork oil? I'm kind of lost.
 
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