Front Springs

[troyw]

Hey All,

Does anyone have the length in inches of the stock springs?
I've been reading a lot on the mod threads, and I'm double checking
myself on the Hyper Pro springs (30mm lower). If I get a Corbin seat
maybe by the end of the year, I'd ask them to lower it an inch or so,
so I may just end up going the Race-Tech front springs way. They have
springs for our bike, but I also have a set of the stock springs from my
"old" Honda VTX 1800, which are rated at .87 spring rate. Our springs
are .80 stock. I'm thinking it might work, except for the beefier fork diameter
might not let me drop the springs in.
Anyway, anyone ever measure the stock springs?

Also, I've been reading a lot on the airbox mod. Anyone else do it and have
it on a dyno to verify that it actually works?

Thanks!:rockon:

- Troy

 

[Hellgate]

Troy, so you are asking if a short spring will lower you ride height? Remember that for aftermarket springs you'll need to make a space to set the preload tension. With the Race Techs they come with a pipe that you cut to the length you want. Net-net, you keep your stock ride height with an aftermarket spring. The only way to lower it is to slide the forks up in the triple clamp.

 

[troyw]

LOL! Definitely know that a lower spring will lower the ride height.
That's some common sense...:spank:
What I was asking was what the length of the stock FZ6 fork spring is.
I'd like to compare them to the VTX 1800 springs I have so that perhaps
I can drop them in, since they are a .87 spring rate compared to the .80 rate
of the stock FZ6 ones. It's a temporary fix, if they'll fit, until I can get some
Race Tech springs.
The thing about lowering the ride height is about it being a little awkward for
me being so tip toed. My first thought was to get the Hyper Pro springs
that bring the bike down 30mm and improve the springs. But, as I get more
confident on this bike, and realize I'm not on a huge cruiser anymore, I'm not
so sure I want sacrifice any lean angle. Know what I mean?

I think I could make some PVC spacers for these traditional forks, yes?
To adjust preload in the front if the VTX springs are shorter than the stock FZ6 springs.
That's what I'm after. The VTX springs are just over 11 inches long.

- T.

 

[Denver_FZ6]

From service manual:

Fork spring free length
354.0 mm (13.94 in)
Limit
347.0 mm (13.66 in)
​

The 'limit' being the point which the springs have taken a 'set' and time to be replaced.

 

[bmccrary]

Not sure on the demensions, but you could indeed lower the front end with some shorter springs. Your sag rates will be all sorts of funky, but thats your call.

I would suggest an aftermarket seat with the sides trimmed down. That has seemed to help alot of people on this forum.

-bryan

 

[troyw]

Well, as I've said, I'm thinking twice about lowering at all. I'm not sure
I want to.
My goal was, thanks to Denver, to find out what length the stock springs
are. If I try to put the VTX heavier springs in temporarily to try it,
I'd have to cut new PVC spacers to match the preload and stock ride height.
Thanks for the info...:thumbup:

T.

 

[SovietRobot]

If you cut the springs then you have to have longer spacers.
Don't do it. If you need to lower the front end, just lower the forks in the triple clamps(or lower the clamps whichever way you see it)

 

[troyw]

Cutting springs? Wha.....?
Again, I'm thinking twice about lowering, and I'm thinking about putting
in VTX heavier rate springs and cutting a SPACER to fit. This is a temporary
fix until I can afford springs from either Race Tech or Hyper Pro.

NOT SURE I WANT TO LOWER THE BIKE WITH SPRINGS.
NOT CUTTING SPRINGS. I KNOW IF THE SPRINGS ARE SHORTER I'D NEED
LONGER SPACERS.

I should be able to use PVC for spacers, right?

Thanks again, Denver, for the measurement.

:thumbup:

T.

 

[CombatPenguin]

I'm pretty sure pvc pipe wouldn't be the best things for spacers. If your using it just to make a template for when you cut the real spacer sure but I won't trust it using it as the real spacer. It's stong but does shatter pretty easy.

 

[troyw]

Progressive suspension and GMD Computrack, a suspension company
that sets up mainly race bikes, told me I could use PVC before. It's always
seemed odd to me, but I guess it shouldn't.
I don't know...I am selling a few items on Craigslist Atlanta & on Ebay to
get money for springs, so I can just wait a bit to get the real deal and not have to do it again. I just don't want to wait long, as the brake diving is quite
pronounced. Strange that it's set up that way. Being about 130 lbs., I can't
get the rear shock to move much, even with preload set on only 2.

PVC can shatter? Wow. I never heard that before. I've used it in cruisers
with Progressive Suspension installs where it calls for PVC spacers in the
instructions. Of course, the demands on cruisers aren't quite what they are
with sportbikes...LOL!

- T.

 

[troyw]

Yup...just sold the last of the VTX 1800 parts.
I think, for now, I'm leaving the ride height the way it is, and
I'm going for the Race Tech spring set for this bike in either
the .95 or the 1.0 weight. Nice n' stiff for the twisties.
I'll likely go .95 because I weigh only around 130 lbs.

I think the general consensus is that straight rate springs are
more consistent and (maybe) better. At least that's what I've heard
more. Do I really know the diff on a racetrack? Nope.
As long as the bike carves like a knife still, and doesn't dive on braking
so much, I'm happy.

- T.

 

[troyw]

Was told by GMD computrack, the racing suspension folks, that springs aren't my problem. It's damping. They suggest emulators, and if I still think I need stiffer springs to go no higher than .90 because I only weigh about 130 lbs. They said
if I just drop heavy springs in now, I'd turn the bike into a pogo stick. So, I guess
I'll save up for the valves or emulators & a bit heavier fork oil.
I hadn't expected to hear that advice, but those guys really seem to know their
stuff. Anyone here use the Gold Valves or emulators? What was the result?

- T.

 

[CombatPenguin]

I know a few people on here used the emulators and they seem to like them. I ordered a matris fork kit which is springs and emulators (that don't require you to mod the damper rod) and lets you have preload adjustments (the cons there expensive) If you really want to get the most adjustments you could do the r6 forks. Those will give you full adjustability.

 

[troyw]

After all the talk about installing valves in the forks, I went and ordered
the .95 kg Race Tech springs and some 20 wt oil. I've just gotta try stuff
out for myself to see who's right. I know GMD knows what they're talking
about, but the dealer where I bought the bike from has a guy in service who
worked for Traxxion and thought I ought to start with springs and new fork
oil. He actually suggested I buy the .95 springs, even though I'm only 130 lbs.
We'll see. If it turns into a pogo stick, then GMD was absolutely right, but I
know I'll end up installing valves anyway. I think I'm keeping this bike for
a while...but I've said that before too...

T.

 

[DefyInertia]

130 pounds, 0.95, and 20Wt!?!?

That's no good. You have definitely cured the dive though...lol

Should go with emulators or R6 forks or some other damping
related mod.

Glad you decided not to lower it

After all the talk about installing valves in the forks, I went and ordered
the .95 kg Race Tech springs and some 20 wt oil. I've just gotta try stuff
out for myself to see who's right. I know GMD knows what they're talking
about, but the dealer where I bought the bike from has a guy in service who
worked for Traxxion and thought I ought to start with springs and new fork
oil. He actually suggested I buy the .95 springs, even though I'm only 130 lbs.
We'll see. If it turns into a pogo stick, then GMD was absolutely right, but I
know I'll end up installing valves anyway. I think I'm keeping this bike for
a while...but I've said that before too...

T.

 

[troyw]

So, you're saying I just wasted my money?
I double checked with this guy who worked at Traxxion, and he said 'yup, .95's'
I thought they might be a little stiff, but he said the thicker oil would slow up
the rebound. I don't have the $500-700 for emulators or R6 forks. Just don't
have it. If this doesn't work, I'll buy the revalve kit and figure out how to install
it myself. I'd like to have a pro set it up, but with uncertainty in the job scene,
I'm not going to spend the coinage right now.

BTW, I do like a very stiff setup on suspension. Not so much that I'm losing
traction, but stiff. I set up my VTX that way, rear preload almost all the way up
and front springs were .95 Race Techs as well. But, that's a 760 lb. bike.
Now, Race Tech's website did have .95 kg in the range of acceptable rates for
me also. I will add that I'm not taking off the forks now, so I'm just going to
pump out as much oil as I can, so there'll be a bit of a mix. Might not be 20 wt
when I'm done. Trial & error I guess. I've always managed to figure it out.
We'll see.

- T.

 

[DefyInertia]

So, you're saying I just wasted my money?
I double checked with this guy who worked at Traxxion, and he said 'yup, .95's'
I thought they might be a little stiff, but he said the thicker oil would slow up
the rebound.

from the racetech website - this is why I reacted the way I did...

04-08 Yamaha FZ6

Rider Weight (without gear): lbs OR kg

Rider Weight: 130 lbs.

FRONT FORK SPRINGS
Recommended Fork Spring Rate for Street: 0.827 kg/mm (use closest available)
Stock Fork Spring Rate: .800 kg/mm (stock)

The recommend 0.892 for "racing". that means you're going fast at the track...not riding at a spirited pace on the street.

I don't have the $500-700 for emulators or R6 forks. Just don't
have it. If this doesn't work, I'll buy the revalve kit and figure out how to install
it myself. I'd like to have a pro set it up, but with uncertainty in the job scene,
I'm not going to spend the coinage right now.

Who has ever spent 500-700 on these monds? You've not spent over $100 and IMO are moving in the wrong direction.

BTW, I do like a very stiff setup on suspension. Not so much that I'm losing
traction, but stiff. I set up my VTX that way, rear preload almost all the way up
and front springs were .95 Race Techs as well. But, that's a 760 lb. bike.
Now, Race Tech's website did have .95 kg in the range of acceptable rates for
me also.

See above

I will add that I'm not taking off the forks now, so I'm just going to
pump out as much oil as I can, so there'll be a bit of a mix. Might not be 20 wt
when I'm done. Trial & error I guess. I've always managed to figure it out.
We'll see.

- T.

I did a write-up in the "how to" section. You probably already have a handle on how to actually do the mod though. Not hard...especially if you leave the forks on.

Good luck :thumbup:

 

[troyw]

Yes, I saw that. I may have gone too heavy, but I would think the guy from Traxxion knows his stuff too. But, so does GMD computrack, and they're
giving me different info. The guy from Traxxion seemed to know what kind
of forks this bike had, and seemed pretty sure. Thing is, everyone I've talked
to has a different set of info on this, and I'm getting kinda tired of that.
I can't really make a good decision because everyone is different. All I have
is my own past experience and Race Tech's spring rate calculator, which as you
pointed out says I should have bought the .90 rate springs. They're probably
already shipped, and I might get slapped with a restocking fee. I'll check it
out though. What is the worst that can happen here? The only thing that
worries me is being so stiff my front skips off a bump and I lose traction.

You say I'm going down the wrong path. GMD agrees with you. You may be
right. Traxxion guy says I'm on the right track. He might be right because
they know their stuff too. Who's right? Who knows. We've got a handfull
of guys on this forum who did just what I did and loved it. Of course, they're
heavier than I am. I can barely move the back shock spring, and it feels
great on the road to me. No hopping or weirdness. I'd like them to be even.
Right now, I put on the brakes and it uses up almost all of the travel. It's
way too soft with very little damping.
I have indeed spent over $100 dollars to get springs and fork oil. The $500
comes from the emulators, which are $170, then the labor for install and the
professional setup from GMD Computrack. I don't have the money, and I'll
do a lot of things myself, but I'm not going to try to set up emulators or
valves because I don't know much about that end of things. I'd like to learn,
but I'm better at tuning a bike's engine than suspension.
Right now I'm trying to sell a gorgeous 6 string bass so I can free up some
money to get this right. Honestly though, I don't mind the springs being
on the stiff side...but I do hear you, and you could be right. But so could
every other person giving me advice and pulling me in all directions...
Cruisers are much more simple...but not as much fun.

- T.

 

[Hellgate]

.95 is way too stiff of a spring. I ran .90 and I weight 175. You are going to have zero sag. The whole point of suspension it to have it move over the bumps and keep the tire on the ground, you are going to richochet with each bump! Once you get them send them back. In fact I'd guess the stock spring is fine. I'm really confused on what you want to acheive. If you want the bike lower just slide the fork up in the the triple clamp and buy a lowering shock.

Here's what Race Tech recommends for you for street riding:

Rider Weight: 130 lbs.

FRONT FORK SPRINGS
Recommended Fork Spring Rate for Street: 0.827 kg/mm (use closest available)
Stock Fork Spring Rate: .800 kg/mm (stock)

Honestly, I wouldn't bother. Just change the fork oil to 10 or 15 weight and go ride.

I don't know about a cruiser being simpler, a motorcycle is a motorcycle and basic rules apply.

 

[troyw]

NOT LOWERING THE BIKE.
Wow...I've said that a bunch of times now, I think.

What I'm trying to achieve is the same is what I achieved on every other bike I've had, which is a better performing front end. I've had 4 Honda Magnas that I put much stiffer front springs in and the bike performed much better.
The VTX 1800 I just had I put .95 Race Techs in. The stock rate was .87,
and I actually didn't think the .95s were quite stiff enough, although they
didn't sag much at all when I got on the bike, maybe 20mm.
The stock springs must be too soft for this bike, and the oil too light. As I've
said, I'm about 130 lbs, and I'm getting 45mm of sag. Just fork oil
isn't going to change that? I may agree with you that going from a .80 to
a .95 spring may be too much. GMD said the same thing, but I've bucked the
trends before and it turned out fine. But, again, this is physics too. I'm
calling the dealer to tell them I made a mistake, and to re-order the .90
springs. That's not that much of a difference. Even GMD told me .90
might be nice...might be. I won't know until I try.

Oh, Pete, didn't you sell those .90 springs? What did you end up with?