suspension improvement and adjustment

meadeam

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I've had my FZ6 for several weeks now, and have put it through it's paces in the twisties. I'm not an advanced rider, but I want more out of the suspension. The front end dives under breaking, and feels unstable in turns. It is very, very soft and springy. It may actually be low on oil; I'll find that out soon.

I've just ordered racetech springs for my weight and riding style, 5wt oil, and cartridge emulators. I will adjust sag front and rear for my weight as well. Have you all had noticeable improvement with the racetech products? Will I need to also upgrade the rear to fully reap the benefits? At some point I think I may end up replacing the rear shock entirely if I find I want more out of the bike. I do plan to do some track days. I don't want to get too carried away with the FZ though, as at some point the solution to everything is to buy and R6.

I'm also replacing the original, circa 2007 tires with a pair of Battlax Hypersport S22. My racer/track day enthusiast friend recommended Dunlop Q4 as his track day tire of choice, and the Battlax as close second for more street than track. I probably won't be on the track as often as he is so I chose the Battlax.

Thanks in advance for any experience you can share with the racetech stuff.
 

Gary in NJ

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I have Racetech springs and GVE in my FZ6. The mod made a dramatic difference - the difference between keeping the bike and selling it. In my opinion, the 5wt oil is too light, I'm fairly certain I used 15wt.oil. I used 0.85kg springs filled the forks with an air gap of 130mm and set the GVE at 3 turns. Your weight and riding style will determine your final settings.

I've used Racetech GVE's many times in the past and consider myself an expert at the installation. If you have any questions, don't hesitate to ask.
 
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meadeam

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I have Racetech springs and GVE in my FZ6. The mod made a dramatic difference - the difference between keeping the bike and selling it. In my opinion, the 5wt oil is too light, I'm fairly certain I used 15wt.oil. I used 0.85kg springs filled the forks with an air gap of 130mm and set the GVE at 3 turns. Your weight and riding style will determine your final settings.

I've used Racetech GVE's many times in the past and consider myself an expert at the installation. If you have any questions, don't hesitate to ask.

Awesome, thanks! I'm having them installed, but I will probably need to tune them at some point.

I was curious about oil weight... I'm 165lbs and I do like to ride fast on the ridges and hollers here in Kentucky. I wasn't sure if I'd give up too much compliance if I went to 10 or 15 weight. Stock is 2.5, so I figured I would try 5. We'll see.

Thanks again!
 

Gary in NJ

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When installing the GVE's the damping rods are drilled out so there is NO damping provided by the rods - all damping occurs at the valve. The GVE can pass a lot more oil than the small holes that were in the damping rod. I would strongly suggest 15wt fork oil.
 

meadeam

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When installing the GVE's the damping rods are drilled out so there is NO damping provided by the rods - all damping occurs at the valve. The GVE can pass a lot more oil than the small holes that were in the damping rod. I would strongly suggest 15wt fork oil.

Ok, sounds like good advice then. I didn't consider that the rod would no longer be dampening.
 

meadeam

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Forgot I'd posted this and thought I'd write a follow up...

The Racetech springs and GVEs made a huge difference. The bike is much more stable getting on/off the brakes and throttle. I also installed Battlax Hypersport S22 tires. The difference is night and day from the stock setup. I'll probably change out the shock spring as well, and do a bit more tuning.
 

Gary in NJ

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Glad to hear. I've used the GVE's in every bike I've owned with damping rods since the mid-90's (over a dozen bikes). They are the difference between keeping a bike and selling it.

I still need to find a cost-effective solution for the shock. I haven't looked for a while...maybe its time again...
 

FinalImpact

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I'd suggest over filling the forks by 25 to 35mm with 7.5 wt. The seals do not seem to be affected and this alone reduces dive both stock, moded and R6.

Running an R1 rear shock. Shock was opened and revalved for FZ needs, FZ spring and aftermarket adjustable collar added. Bike is rock steady over all paved terrain. There is sticky in the mod section. Have a look. Its effective and affordable for our application as it basically bolts in.
 

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Hi guys, I want to upgrade the front suspension, I found the Race Tech springs on eBay for $96, but I see there are diffrent versions - I.E. 0.85kg, 0.95kg, 1.0kg ? What does it mean and what's recommended for a 170lb rider? Alos, what do you mea by GVE's ? Any help would be much appreciated, I'm new to this. Thanks!
 

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Hi guys, I want to upgrade the front suspension, I found the Race Tech springs on eBay for $96, but I see there are diffrent versions - I.E. 0.85kg, 0.95kg, 1.0kg ? What does it mean and what's recommended for a 170lb rider? Alos, what do you mea by GVE's ? Any help would be much appreciated, I'm new to this. Thanks!

Maybe Gary can help with this? @Gary in NJ
 

Gary in NJ

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For a 170lb rider you'll want to use the 0.85kg/mm springs. $96 is a good price, make sure they are RaceTech springs and aren't rebranded generic springs. The Race Tech part number should be FRSP S373285 (the last two digits are the rate)

The GVE are Racetech Gold Valve Emulators. Using a Race Tech Gold Valve Emulators (part number FEGV S4101) and linear-rate fork springs you can significantly improve the damping (compression & rebound) of the conventional damping-rod forks used on the FZ6. I’m not going to go into a lot of explanation on this as there is great documentation on the Race Tech website (racetech.com) as well as dozens of technical articles on the internet, but here is some info from Race Tech’s FAQ:

“Damping rods while inexpensive to manufacture have major limitations. To create compression damping, oil is shoved through a hole or holes. Shoving oil through holes creates very little resistance to flow at low vertical wheel velocities as when hitting a dip or gully or applying the front brakes. This allows the forks to shoot through the travel fairly easily, diving or bottoming in these situations. On the other hand when the wheel hits something square edge, especially at speed, it needs a lot of oil to pass through the damping holes very quickly. Unfortunately the nature of shoving oil through holes is that as the wheel velocity increases the damping force increases with the square of the velocity. In other words if you double the velocity you get four times the force. This means the hole basically "hydraulic locks" resulting in a harsh spike. Damping rods give the worst of both worlds; they are both too mushy and too harsh at the same time.

An Emulator is a valve that sits on top of the damping rod and is held in place with the main spring. To install them simply remove the damping rods and drill out the existing compression damping holes so they are so large they do not create any appreciable damping. Then during reassembly simply drop the Emulator on top of the damping rod. The Emulator creates the compression damping of a state-of-the-art cartridge fork. The ride is both firmer and plusher than the damping rod and is completely tuneable.”


I’ve used Gold Valve Emulators many times in the past (street and dirt bikes) and have always gotten outstanding results.

When using the Gold Valve Emulator you’ll need to use linear-rate springs. Progressive-rate fork springs just don’t work in a fork that has proper compression valving. The problem with progressive-rate springs is they attempt to do what proper valving actually does. Progressive-rate springs can have unpredictable or undesirable performance characteristics; too soft in the initial stroke (most notable with brake dive) and too stiff in the later portion of the stroke (resulting in a harsh ride). Preloading doesn’t solve the problem, it just transfers the problem to a different portion of the stroke or eliminates that usable portion of the spring…at which point you might as well be using a linear-rate spring.
 

matiasem

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For a 170lb rider you'll want to use the 0.85kg/mm springs. $96 is a good price, make sure they are RaceTech springs and aren't rebranded generic springs. The Race Tech part number should be FRSP S373285 (the last two digits are the rate)

The GVE are Racetech Gold Valve Emulators. Using a Race Tech Gold Valve Emulators (part number FEGV S4101) and linear-rate fork springs you can significantly improve the damping (compression & rebound) of the conventional damping-rod forks used on the FZ6. I’m not going to go into a lot of explanation on this as there is great documentation on the Race Tech website (racetech.com) as well as dozens of technical articles on the internet, but here is some info from Race Tech’s FAQ:

“Damping rods while inexpensive to manufacture have major limitations. To create compression damping, oil is shoved through a hole or holes. Shoving oil through holes creates very little resistance to flow at low vertical wheel velocities as when hitting a dip or gully or applying the front brakes. This allows the forks to shoot through the travel fairly easily, diving or bottoming in these situations. On the other hand when the wheel hits something square edge, especially at speed, it needs a lot of oil to pass through the damping holes very quickly. Unfortunately the nature of shoving oil through holes is that as the wheel velocity increases the damping force increases with the square of the velocity. In other words if you double the velocity you get four times the force. This means the hole basically "hydraulic locks" resulting in a harsh spike. Damping rods give the worst of both worlds; they are both too mushy and too harsh at the same time.

An Emulator is a valve that sits on top of the damping rod and is held in place with the main spring. To install them simply remove the damping rods and drill out the existing compression damping holes so they are so large they do not create any appreciable damping. Then during reassembly simply drop the Emulator on top of the damping rod. The Emulator creates the compression damping of a state-of-the-art cartridge fork. The ride is both firmer and plusher than the damping rod and is completely tuneable.”


I’ve used Gold Valve Emulators many times in the past (street and dirt bikes) and have always gotten outstanding results.

When using the Gold Valve Emulator you’ll need to use linear-rate springs. Progressive-rate fork springs just don’t work in a fork that has proper compression valving. The problem with progressive-rate springs is they attempt to do what proper valving actually does. Progressive-rate springs can have unpredictable or undesirable performance characteristics; too soft in the initial stroke (most notable with brake dive) and too stiff in the later portion of the stroke (resulting in a harsh ride). Preloading doesn’t solve the problem, it just transfers the problem to a different portion of the stroke or eliminates that usable portion of the spring…at which point you might as well be using a linear-rate spring.

Thank you very much for the explanation!
 

Sdaniels

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When installing the GVE's the damping rods are drilled out so there is NO damping provided by the rods - all damping occurs at the valve. The GVE can pass a lot more oil than the small holes that were in the damping rod. I would strongly suggest 15wt fork oil.

Gary, do you remember which brand of fork oil you used & what length you ended up with on the spacers? I've got a couple of pieces of pvc that I think might work. If the stock preload is the same as what RT recommends (10mm), it should...but I have no idea what stock preload setting is.
 

Gary in NJ

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I use Maxima 15w fork oil.

The preload is just a starting point. Final preload will be determined through sag measurements, both static and loaded. For that reason I always install adjustable fork caps. It makes setting sag and any future adjustments much easier.
 

Sdaniels

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I use Maxima 15w fork oil.

The preload is just a starting point. Final preload will be determined through sag measurements, both static and loaded. For that reason I always install adjustable fork caps. It makes setting sag and any future adjustments much easier.

Yeah, I'd do the same thing but I'm still trying to convince my son to do the springs/emulators. He hasn't even put 50 miles on the bike. Told me he just wants to ride it for a while. He'll come around....;)
 

Sdaniels

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He'll come around that day that he has to grab a handful of brakes in an emergency situation and the forks bottom out...and the rebound bucks him like he's in a rodeo.

Well I hope it doesn't come to that. It was easier when he still lived with us. I could do things to his bike without even asking.
 
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