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Discussion Starter · #1 ·
It depends what you weigh - naturally.
I weigh 78kg (175 lbs) in riding gear.I have just had Andreanni Cartridges and a Nitron shock fitted.
The cartridges come with 0.78 kg/mm spring.The standard Yamaha spring is 0.76 kg/mm.
The Nitron shock is currently fitted with a 0.95 kg/mm spring and this is too hard.I will be trying a 0.9 and a 0.85 when we get them.
The standard Yamaha spring is 10 kg/mm as measured on the suspension specialist's electronic measuring device.

So I am using virtually standard springing on the front and softer on the rear and the springing is still too firm.The bike does handle great now but I will get it even better.The difference is in the damping.Fork dive on this bike,for someone my weight, is due to badly controlled damping as is excessive squat and bad compliance on the rear.

I hope this helps other riders make improvements to their bikes.
 

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We are within few lbs of each other. My fork springs are .85 kg/mm with 10W oil.

The rear I always felt the oem spr8ng was too stiff for me. The ZX-10 shock comes with a 9.1 kg/mm. I tested the 9.7 kg/mm (like the oem fz09) and still confirm the same. Too much free sag and got to a point where the bike will drop only 21mm when I sit on it. 9.1 back on now.

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A bike with long travel suspension like the FZ -09 should not be set up with the same sag numbers as a sportbike. Just sayin. A slightly stiffer rear spring should fix all handling issues...from I hear and read.
 

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To me it feel like there is way to much compression in the beginning of the stroke and not enough in the mid and end, this will make the spring feel to stiff, I was going to try longer pull rods but have given up on that idea it seems the more miles I put on the bike the better I like it on the roads I ride. I now run the spring on the second to soft on the preload with rebound out one and a half turns to me this is much better than full hard like I was running in the beginning. Lower end stuff seems to take longer to break in. One thing I noticed is there is no air bleeds on the forks, my 2013 yamaha wr250 has them and my 2004 honda xr250 also has them I've also put them on lots of DR 650S I've set up motion pro makes a kit with a drill , tap and bleeders. Does anyone know if air build up in the forks is a problem. RR:cool:
 

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Discussion Starter · #5 ·
A bike with long travel suspension like the FZ -09 should not be set up with the same sag numbers as a sportbike. Just sayin. A slightly stiffer rear spring should fix all handling issues...from I hear and read.
What a stiffer rear spring does is limit movement.If your problem is badly controlled movement due to poor damping,limiting the movement will reduce the effect the bad damping has - no movement,don't need to control it.A suspension is designed to move,you should aim to have as much well controlled movement as possible.You should not be stopping suspension movement with a stiff spring or excessive preload to cover the deficiencies in the damping.
Trust me ,I have a Suzuki bandit that just soaks up bumps of all sizes with virtually no effect on the handling.Both bikes have been set up by the top suspension tuner in my country - the guy all the top racers go to for advice
 

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Discussion Starter · #6 ·
To me it feel like there is way to much compression in the beginning of the stroke and not enough in the mid and end, this will make the spring feel to stiff, I was going to try longer pull rods but have given up on that idea it seems the more miles I put on the bike the better I like it on the roads I ride. I now run the spring on the second to soft on the preload with rebound out one and a half turns to me this is much better than full hard like I was running in the beginning. Lower end stuff seems to take longer to break in. One thing I noticed is there is no air bleeds on the forks, my 2013 yamaha wr250 has them and my 2004 honda xr250 also has them I've also put them on lots of DR 650S I've set up motion pro makes a kit with a drill , tap and bleeders. Does anyone know if air build up in the forks is a problem. RR:cool:
In a way you are correct.Standard damping pistons ,generally have fluid pathways that are too small to flow damping fluid correctly at high damper speeds,so the damper locks up when you hit a sharp bump.Have a look at the difference between a Racetech valve piston's holes and a standard Showa piston.The Racetech valves holes cover 3 times the area.

The air gap on road bike forks is set by the oil level
 

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There a lot to it than just port size. Shims stack, shim preload, dish piston... shock technology keep a lot of very smart people employed all year around. There so much more to it than oil going through holes.

Someone I know who wanted to build shock few years ago told me it's not that difficult to buolt shock. All there is its oil going through holes with shim stacks.

I told him great, you just understand about 20% of whats going on. The hard part is the other 80%!

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Yeah, understanding the basic idea isn't the same as knowing how to get it right for a particular bike, rider, etc.
 

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So Paul the air buildup in the forks doesn't need to be bled like dirt bikes ? and yes, getting suspension setup right is a fine art. Knowing the basics is only the very beginning, throw in personal prefference and the guys realy earn their money . RR:cool:
 

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What a stiffer rear spring does is limit movement.If your problem is badly controlled movement due to poor damping,limiting the movement will reduce the effect the bad damping has - no movement,don't need to control it.A suspension is designed to move,you should aim to have as much well controlled movement as possible.You should not be stopping suspension movement with a stiff spring or excessive preload to cover the deficiencies in the damping.
Trust me ,I have a Suzuki bandit that just soaks up bumps of all sizes with virtually no effect on the handling.Both bikes have been set up by the top suspension tuner in my country - the guy all the top racers go to for advice
A Bandit? OMG....dude this is 2014 !! Go see my buddy Graeme Crosby in Matakana. Tell him Bob sent.
 

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Discussion Starter · #11 · (Edited)
A Bandit? OMG....dude this is 2014 !! Go see my buddy Graeme Crosby in Matakana. Tell him Bob sent.
Graeme lives about 50 km from me.I heard he is more interested in golf,now.:p
He would think the 1250 would be some kind of UFO.He has recently restored Kawasaki Z900.So tell me again about it being 2014:rolleyes:
I often go through Matakana seeking quiet winding roads.
I still have the 1250 and have embarased R1 riders on a windy road.As my brother commented (also has a 1250) how embarasing to be chased down by two "old man's bikes"
I bought the 09 because it is the only bike in decades that has the flat torque curve and proper seating position that I love the Bandit for.
 

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Discussion Starter · #12 ·
There a lot to it than just port size. Shims stack, shim preload, dish piston... shock technology keep a lot of very smart people employed all year around. There so much more to it than oil going through holes.

Someone I know who wanted to build shock few years ago told me it's not that difficult to buolt shock. All there is its oil going through holes with shim stacks.

I told him great, you just understand about 20% of whats going on. The hard part is the other 80%!

Sent from my SAMSUNG-SGH-I337 using Tapatalk
Of course,but before you can properly control damping fluid flow with the shim stacks,you need to allow it to flow freely to the shim stack.This is what the standard pistons never seem to allow,sufficiently.
 
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