Aftermarket spring and is that a PVC pipe?

[ragedigital]

My guess is that someone added the emulators cause they found them cheap somewhere and added the pvc spacer to help with the bouncy stock springs.

[slayermd]

No, I didnt take the forks all the way off. I just uncapped it.

when you uncapped it did it feel like it wanted to shoot out ?
are you changing your springs with the forks still on the bike ?

if possible can u take some pics of how your bike sits .. id like to do somthing like this over winter if i dont have to take forks completely off ..

Ill get a picture up for you in a few hours. Yeah, when the cap came of the washer and pipe kinda shot out. From what I have heard off of some SV site that you can change the oil and springs with everything still on the bike. I guess as long as you dont have to replace any seals that would be ok.

That spring looks to be stock. Mine looked exactly the same way... I replaced mine with RaceTech springs.

Hmm.....I like to hear that.

Slayer,
either your springs are shot or the lady did not know what she was doing as those emulators DO NOT work correctly with progressive wound springs.

Whilst RaceTech are nice the price I found a bit excessive and found a local (3 miles or so away) spring maker at about half the price and offering the same range of forces.
By all means use RT site to work out the spring rate and oil viscosity and set the emulators up accordingly (0-7 turns on mine set at 3.5 for now)

see:-http://www.saltmine.org.uk/fzr/fork.html

for a how to etc.

You will see from that article that the damper rods also need modifying, best to see if yours have been done !!!! or you are wasteing time putting in the emulators as stock they do not see enough oil for them to work
Geo

Thanks for the info George. I can look for some local spring makers but I really dont mind paying for the Racetechs. Ive have been recommended at .850kg from them. Ive been wondering about the oil weight and have gone with 15w. Ill have to pull out the forks later this week to see if the damper rods have been drilled out. I guess I will have to order some new seals too.

[reelrazor]

My guess is that someone added the emulators cause they found them cheap somewhere and added the pvc spacer to help with the bouncy stock springs.

Stock, the preload spacers are longer than that-about 6 inches (and steel-at least mine were-part # 1WG-23118-00-00). My '96 had straight rate springs from the factory. Yamaha has had a love/hate deal going with progressive wound(not Progressive Brand) springs for a long time. I dunno, maybe they used them on FZR's for some model years.

But George is right, the emulators are going to work better with a straight rate spring on top of them. I think they lift off of the damping rod as the light spring rate coils start to compress instead of staying on the damping rod and metering oil full time like they are supposed to.

[Fuser]

Yup, pulled one out.

Slayer,
either your springs are shot or the lady did not know what she was doing as those emulators DO NOT work correctly with progressive wound springs.

Whilst RaceTech are nice the price I found a bit excessive and found a local (3 miles or so away) spring maker at about half the price and offering the same range of forces.
By all means use RT site to work out the spring rate and oil viscosity and set the emulators up accordingly (0-7 turns on mine set at 3.5 for now)

see:-http://www.saltmine.org.uk/fzr/fork.html

for a how to etc.

You will see from that article that the damper rods also need modifying, best to see if yours have been done !!!! or you are wasteing time putting in the emulators as stock they do not see enough oil for them to work
Geo

To clarify this myth that has been touted by race tech, the emulators will most certainly work with progressive rate springs. The reason they claim that however is that the emulator should be dialed in to control a specific spring rate while a progressive rate spring will vary above and below this target rate.

Now damping is tuned to "feel" and is a balance of control and ridedability (if you rode a critically damped bike you'd likely rattle your teeth out). So what I'm saying is you can tune the emulator to control a progressive spring there is just no chart available to tell you how much to preload the emulators adjuster.

So saying the previous owner didn't know what she was doing is a little rash. She likely just took the time to tune the bike herself by feeling how her bike was responding rather than using a recommended "catch all" suggestion.

[Fuser]

My guess is that someone added the emulators cause they found them cheap somewhere and added the pvc spacer to help with the bouncy stock springs.

Stock, the preload spacers are longer than that-about 6 inches (and steel-at least mine were-part # 1WG-23118-00-00). My '96 had straight rate springs from the factory. Yamaha has had a love/hate deal going with progressive wound(not Progressive Brand) springs for a long time. I dunno, maybe they used them on FZR's for some model years.

But George is right, the emulators are going to work better with a straight rate spring on top of them. I think they lift off of the damping rod as the light spring rate coils start to compress instead of staying on the damping rod and metering oil full time like they are supposed to.

To continue my last post, this is very possible. Do you have any evidence to support it though? I still had quite a bit of preload when I set my sag on my progressives.

I know the previous owner raced the bike but are you going to be using it for race or street? If it's race only I'm with everyone else and suggest getting it sprung properly for your weight.

[reelrazor]

To continue my last post, this is very possible. Do you have any evidence to support it though? I still had quite a bit of preload when I set my sag on my progressives.

I know the previous owner raced the bike but are you going to be using it for race or street? If it's race only I'm with everyone else and suggest getting it sprung properly for your weight.

No, I have NO evidence to support it. Just a theory bouncing around in my head. And, unless your sag/preload starts the progressive spring into coil bind, you still have a very light spring rate to hold the emulator down. I would think that any fast input would be enough to push the emulator off the damping rod-at least momentarily.

I do know that damping's job is to control spring motion. I think that job is complicated by having to deal with a compounded rising rate (compounded because a progressive wound spring has a rising rate, plus the decreasing air space above the oil constitutes a rising rate spring in itself).

[slayermd]

I know the previous owner raced the bike but are you going to be using it for race or street? If it's race only I'm with everyone else and suggest getting it sprung properly for your weight.

The bike is set up for track use only. The bike was prepared by someone who knew FZR's. He raced in the MRA here in Colorado with a FZR400 (see here) that has won a lot of races. She maybe weighed in at 120 and Im at 150ish (I am a twig) so I ordered RT springs according to my weight.

Thank you all for info. I was really surprised to see a PVC pipe in my forks and would have been scratching my head for awhile as to why it is in there.

[Fuser]

To continue my last post, this is very possible. Do you have any evidence to support it though? I still had quite a bit of preload when I set my sag on my progressives.

I know the previous owner raced the bike but are you going to be using it for race or street? If it's race only I'm with everyone else and suggest getting it sprung properly for your weight.

No, I have NO evidence to support it. Just a theory bouncing around in my head. And, unless your sag/preload starts the progressive spring into coil bind, you still have a very light spring rate to hold the emulator down. I would think that any fast input would be enough to push the emulator off the damping rod-at least momentarily.

I do know that damping's job is to control spring motion. I think that job is complicated by having to deal with a compounded rising rate (compounded because a progressive wound spring has a rising rate, plus the decreasing air space above the oil constitutes a rising rate spring in itself).

Very true! The emulator is already trying to control a progressive rate once you bring the air spring into the equation. I'll definately have to look into the possibility of the emulator blowing off.

Now since it's going to be a race bike and I'm not one for thread jacking, I'll leave you to those with race experience! Race tech will definately put you on the right track. Good luck to ya!

[yamaha_george]

To clarify this myth that has been touted by race tech, the emulators will most certainly work with progressive rate springs. The reason they claim that however is that the emulator should be dialed in to control a specific spring rate while a progressive rate spring will vary above and below this target rate.

Now damping is tuned to "feel" and is a balance of control and ridedability (if you rode a critically damped bike you'd likely rattle your teeth out). So what I'm saying is you can tune the emulator to control a progressive spring there is just no chart available to tell you how much to preload the emulators adjuster.

So saying the previous owner didn't know what she was doing is a little rash. She likely just took the time to tune the bike herself by feeling how her bike was responding rather than using a recommended "catch all" suggestion.

Fuser,
You may well be right that it is an urban myth but my man on a MotoGP team as suspension tech believes it, my Ozzy race tech believes it too , go figure,

From a practical point of view having a multiple variables is gonna make it harder all round for pro + the likes of us to tune.

Having a set spring rate with a variable of the emulator is gonna be easier to do, IF you want to be fancy then have multiple choices of pre-load spacers, multiple choice springs with different rates. then you can set your forks up for different tracks with some certainty of repeatabilty.

If that sounds like too much work remember that to get to the emulators you must remove cap, pre-load & spring any way.

I have had my forks apart three times to try a setting each way on my PD's and I have gone back to what my suspension guy said, I was just curious after the GP guy said " Hmm sounds about right for you but you might wanna......"

I would like to pose a general question :-
How many of the list has fully adjustable suspension & how many of you have worked thro the full range with a notebook.

From my days at Yamaha I would be say about 1% of you and those who have altered "the setting" have regretted not made notes to set it back :-}

[Fuser]

I'm just saying that while I don't have the personal experience doing the tuning (thats left to the applications guys), I have seen the dyno curves of Race Techs emulators and Harley Davidsons emlators using both straight rate and progressive rate springs, and the damping remains reasonably consistant. We haven't done any super high speed testing so the idea of the valve actually blowing off under impact load is possible but not likely with the low loads they carry once the actual valve opens.

As far as actually tuning the valve I agree, there's so much going on that I won't attempt to pretend I know what all is going on. I can bounce theory around in my head all I like but still damping is tuned by feel/testing and most definately like you said through documentation. If you wanna take it up a notch you can even do ride reports on a test loop that you know very well. While I've tuned/built plenty of automotive/truck dampers I've only been riding for like a year and I'm still trying to get an idea of whats going on with the bike compared to what adjustments are available. I also don't have a large pool of bikes to compare how they handle (with the exception of harleys but trying to compare the suspension on a HD to a Sportbike is well... a little silly).

so in summary:
1. Emulators do work with progressive rate spring: Fact, if you'd like I can try to track down the dyno curves
2. Just because I say they work doesn't mean that I'm promising it will give you your desired results
3. Progressive rate springs are available in limited rates unless you get something custom
4. For racing I'm with everyone else and suggest contacting Race Tech and getting the bike sprung properly for your weight/riding style

[yamaha_george]

I

so in summary:
1. Emulators do work with progressive rate spring: Fact, if you'd like I can try to track down the dyno curves
2. Just because I say they work doesn't mean that I'm promising it will give you your desired results
3. Progressive rate springs are available in limited rates unless you get something custom
4. For racing I'm with everyone else and suggest contacting Race Tech and getting the bike sprung properly for your weight/riding style

Fuser,
Yup you are right a spring no matter how wound (straight / progressive) it will act as a spring as you say in 2 above you may not get what you want out of the ride.
I personally believe that the removal of an un-required variable (ie progressive springs) will make the whole assembly easier to set up.

I no longer race, but even for GOOD street ridabilty a single rate spring & PD's or emulators as you guys call them make a world of difference to your ride. I compared Race Tech's figures with those from my 2 guys and they were all close the oil weight varied by 5.

The guy who made my springs was ace when measured they were within 0.1% of the 0.85KG recommended and exact to each other.

As to the ride as I said it was spot on BUT me being me I had to twiddle BUT went back to what the guys had said would work.

If any of you decide to update the shocks to the bells & whistles type. for your OWN sake make a note of the settings as they arrive. Then when you are "twiddling" you can check out your new setting .
Riding to work is great for this as it is a repeatable journey.JUST BE SURE TO pack your NOTEBOOK !!!

[shredex]

what size was that PVC pipe?
I might do this to stiffin my front suspension so I can lower my front fairing and have the front fender not hit when I hit a bump.