Fork Springs and Emulators

[Ralgha]

I'm planning to upgrade my fork springs, probably this winter, RaceTech recommends .70kg springs for my weight. How noticeable will the difference be from stock?

How much of a difference would adding RaceTech's Gold Valve Cartridge Emulator Kit make over the new springs? I don't have the confidence to install those myself, so I'd ship my fork tubes to them and have them do it. That would probably add about $400 to the cost of the springs alone (I'd install those myself). Are the emulators worth that extra $400?

I'm not doing track, just twisty roads.

[ForceofWill]

If you're not comfortable doing the emulators yourself, I would just do springs. .70s seem light, how much do you weigh?

[britx303]

Springs alone will always improve the bike,even without emulators.If you are not going to race it,I would skip them as well,but do springs and fork oil(wieght and height). Speaking from doing several FZR emulator setups,you have to bore out the damper rod holes and weld the top rebound orifice,and it does make a major improvement for racing,but I hated it for the street.I agree with Will,.70kg seems light,unless you are not heavy like me

[cbinker]

I wouldn't say his rate is soft, recommended spring rate for me at 185# is .78, which is why i have .8 for my bike. it feels a little too stiff on the front and i have made some adjustments with the forks and rear ride height. seems more comfortable.

[Ralgha]

I weigh 135 without gear on. Sounds like springs only is the way to go, thanks!

[InvisiBill]

According to RT's numbers, .70 is a bit soft, but .75 is a bit stiff. Keep in mind that the stock NewGen springs are already .65, so this won't be a huge change for you (whereas the PreGen uses .44). You're looking at tweaking it a notch or two on the NewGen, but you'd need ~45% stiffer for your weight on the PreGen.

For such a small change, you might consider just cutting down your stock springs. original spring length * original spring rate = new spring rate * new spring length is the formula to figure out the new length or rate.

If you're considering Emulators, check out Ricor's Intiminators. I believe they're a much more sophisticated solution, and they're actually easier to install. They're ~$50 more than Emulators. They're designed to use a relatively large amount of low-speed damping, so you can get away with a slightly softer spring too. With your weight being fairly close to the stock springs' rate, you might be able to keep those if using Intiminators.

[Ghostt]

Cut the OEM springs, Ricor's Intiminators, and set the sag, also don't forget about the rear shock, which it should be okay for your weight, so just dial the sag in, and your set.

[Somchai]

Before getting a new spring or buy anything else just test your forks with an oil level at 100 or 95 mm (Stock = 108 +/- 2 mm).

[Ralgha]

More good advice, thanks. Intiminators sound good and no drilling is the best part.

[cbinker]

at your weight, you might as well save the money.

[supersport]

Find a suspension shop near your place and have them do it.

Contact your local track/road racing organization and ask what are the good local suspension shops in your area. Get a couple of names and if a few of the organizations recommend that same person or shop you know where to go.

$400 on top of the emulators and springs is a lot. You can get a fork rebuilt for $400-$700. If your paying that much, you might as well get a rebuild.

Just for reference, one of the best cartridge you can get for the ninja is a Adreani cartridge.

http://www.motospecialties.com/store...temNum=105/K06

here is the install:

https://www.ninjette.org/forums/showthread.php?t=113288

[Ralgha]

400 includes the emulators, installation, and fork overhaul I think.

So general consensus seems to be that stock springs are close enough for my weight. What if I kept the stock springs and put in the intiminators? What kind of difference would that make?

[InvisiBill]

It would make it better.

Intiminators use a cartridge-style damping system, like modern sportbikes use. The design simply handles a slightly soft spring better than the stock damping system does. You're not actually changing any of the spring characteristics, but the same spring is in the "acceptable" range with one damping system while being "too soft" with the other.

I'm pretty sure those Adreani cartridges are better. However, they also cost 5x what the Intiminators do (their installation charge is more than what the Intiminators cost), and Intiminators have been compared to $1100 fork upgrades. If you're not a pro going all out, I think you'll probably find the Intiminators to be a better value.

For my weight on the 500, I went with a 54% stiffer spring (which is actually still a bit soft for me) as one of my first mods. The massively undersprung forks made it mushy when riding hard and gave a rough ride, due to the springs not being able to properly support the weight. Just getting the right(ish) spring in there made a huge difference in how the bike felt. Due to the NewGen's stiffer springs and your weight, that's probably similar to how your bike feels stock.

Adding the Intiminators smoothed things out. It's not nearly as big an improvement as the springs were, but it is an improvement. The inertia valve is good at absorbing big bumps, while keeping it firm when riding harder. In stock form, I could literally feel every seam in the pavement. With the new springs and the Intiminators, the biggest frost heaves now feel like small cracks used to.

You might still want to upgrade the springs later to make it perfect. Someone with more firsthand experience should be able to give some tips. But with the stock springs being pretty close and the Intiminators handling soft springs better than stock, I think they're probably a great value for you - they'll upgrade you to a shim stack damping system, with the blowoff valve for big bumps, and help compensate for the slightly-soft spring. All in one relatively cheap, easy to install package.


Also, indications point toward the rear spring being too stiff for a lot of people (RT shows it as being good for a ~215lb rider), though at least one smaller person said it was too soft in his actual race testing. You may find some improvement by softening the rear a bit. I don't know of any cheap & easy way to respring the stock shock, but the various GSXR shocks have a wide range of spring rates available. Check your free/static sag numbers and see if the spring is in the right range for your weight.

[Ralgha]

According to Racetech's calculator, the stock rear is too stiff for me. They also list a bunch of springs, can you simply swap springs on the rear shock?

[InvisiBill]

Originally Posted by Ralgha

According to Racetech's calculator, the stock rear is too stiff for me. They also list a bunch of springs, can you simply swap springs on the rear shock?

Originally Posted by InvisiBill

Also, indications point toward the rear spring being too stiff for a lot of people (RT shows it as being good for a ~215lb rider), though at least one smaller person said it was too soft in his actual race testing. You may find some improvement by softening the rear a bit. I don't know of any cheap & easy way to respring the stock shock, but the various GSXR shocks have a wide range of spring rates available. Check your free/static sag numbers and see if the spring is in the right range for your weight.

There's some question about RT's calculator, but it's all I have to go on. rojo is only 160lb, and said the stocker was too soft. However, assuming the rear suspension is pretty similar to the PreGen and 500, RT's numbers seem reasonable. I suggested checking your preload/sag to make sure that the spring really is too stiff for you. If the spring is in the right range, you'll be able to set it up so that both the free and static sag numbers fall in the right range. If the spring is wrong, you won't be able to adjust it so that both are correct at the same time.

[thunderchicken]

Originally Posted by Ralgha

According to Racetech's calculator, the stock rear is too stiff for me. They also list a bunch of springs, can you simply swap springs on the rear shock?

I can save you a ton of heartbreak on this one....
Yes, you can swap rear springs and I ordered mine from Racetech when I also did the front springs. Compressing the spring is a PITA without the proper tools, but once I replaced it I found the O.D. too wide to fit inside the dogbone (66mm O.D. instead of the stock 44mm). Oops. Racetech was cool enough to next-day me a replacement but.... It was wrong too. In both cases they swore up and down it was the right spring for my bike, so I would skip it. If you are set on doing the rear spring (and aren't going to race it) there are a couple good aftermarket spring/shock options which come pre-assembled and will fit

[Foxrider64]

Long story short...you and I weigh about the same- save the money and so just the springs. It is noticeably improved. There is much less dive under braking at speed. I have the race tech .7 springs in my race bike with 10wt oil. Unless you are super competitive there is no need for emulators.