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I beat air to submission
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I weigh 165 and my GSXR-1000's fork springs are too soft for me. I don't think that the average sportbike rider rides their bikes hard enough to warrant stiffer springs. It's kind of like most sports cars. They come from the factory with pretty supple suspension, but if you take them to the track... they have all kinds of body roll, squat, and dive. You have to upgrade their suspension with stiffer springs, thicker anti-roll bars, and better shocks. (or buy proper coil overs).

If they sold cars and bikes with stiffer springs, people will complain. My old Evo IX is considered by many to have too harsh of a ride... but that's why it is known to be one of the best handling cars on the road. And still, if you take it to the track, it'll be considered to be too soft. Suspension all depends on what you plan on doing with your vehicle.
 

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Habitual line-stepper
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Depends on the bike.

the 03-04 ZX-6r rear shock is set up for a 265lb rider.

The shock in the 97-98 version of my bike is set for a 135 pound rider. In 99 they changed it to be suited for a 170 pound rider.

Same thing with most brands of bikes... it's all over the place. GSXR1000's through 05 had a .85kg/mm spring rate, and in 06 it got changed to 1.0, as did the 750 and 600.

So- it really depends. If you're not going to the track and you bike does not bottom out under hard braking, you're most likely ok for the street.
 

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Mediocre Strafer
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Not all, but probably many. Especially Japanese bikes seem designed around a 150lb rider. When you look at RaceTech, remember to use the recommendation for street use unless you specifically want a track bike - they're pretty aggressive with their rates.

The revelation to me was that, particularly with shock springs, a heavier spring with less preload actually gives a smoother ride over abrupt bumps.

KeS
 

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vroom vroom
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490 Posts
kevinwilly said:
Depends on the bike.

the 03-04 ZX-6r rear shock is set up for a 265lb rider.

The shock in the 97-98 version of my bike is set for a 135 pound rider. In 99 they changed it to be suited for a 170 pound rider.

Same thing with most brands of bikes... it's all over the place. GSXR1000's through 05 had a .85kg/mm spring rate, and in 06 it got changed to 1.0, as did the 750 and 600.

So- it really depends. If you're not going to the track and you bike does not bottom out under hard braking, you're most likely ok for the street.
you shure about that
 

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Scoot Jockey/Nomad Trash.
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My rear was set way too stiff for me (145 lbs) from the factory. It had to be set softer just to get my rear tire to hook up in the turns. On the other hand I have a 240 lb friend who needs to get a stiffer spring on his bike due to his weight.
 

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Habitual line-stepper
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bug99_69 said:
you shure about that

oops...

It's only 240lbs.


I was off by a bit. But yearh- it's REALLY fucking stiff. My girlfriend bought an 03 ZX-6r and was complaining about the suspension being harsh, so i did some digging.

Obviously WAY too much for her, as she is all of about 115lbs.

They lighted it a bit for 04, to 220lbs, but changed it to a MUCH lighter spring for the 05 model.


Sounds a bit crazy, doesn't it? But it's true. Kind of a nice change for me when i was riding her bike, as i have been used to being UNDERsprung by about 50 lbs. Being OVERsprung by the same amount is much preferrable.

I'm changing out my shock to one of my stiffer ones for my trackbike, and have already replaced the forks (.70kg/mm stock.... TERRIBLE, as i need .90) with ones from an 04 GSXR1000. Much closer to what i need at .85, but i will buy new springs for them eventually.

I'm kind of a suspension snob.... but if you've ridden a PROPERLY set up bike, you'll be amazed at the difference it makes. It's incredible.

:)
 

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Yea, 6rr rear shock is stiff as hell. Currently looking into getting a much softer spring for my 135 pound self, haha.
 

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www.fixedfocus.us
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theapp said:
Yea, 6rr rear shock is stiff as hell. Currently looking into getting a much softer spring for my 135 pound self, haha.
Its good for me, but then again, I am a fatass....so it works out...Just need the front redone
 

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Gen1 01-05 FZ1s sprung for 140 lb rider.
Gen2 06-07 FZ1s sprung for 200 lb (or more) rider.
In my experience California Suspension Works or Traxxion (written up nationally for Gold Wing suspension success) are reliable for getting the ride and handling the rider wants.
Both have pleased members on a veriety of bikes and purposes, street,track,dirt,dual sport.
 

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Not for me. Im a paper weight and Im riding the dreded 03 636 suspension. The 04 is slightly better and the 05-05 was made for a ~150 lb rider.


Everyone designs bikes for people my height and weight, and I pick the one bike on the market designed for a 265 lb rider. geez:lao
 

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Cheap Bastid
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On the street, spring weight is a function of rider weight & to a point, rider ability. On the track, it's a function of rider weight and how fast you ride. The faster you are the heavier springs you'll need.

That's why, although most sportbikes are sprung for a 150-160lb street rider, riders heavier than that often don't need to re-spring their bike where as a 140lb racer may need stiffer springs & possibly a new rear shock.

If you're 200lbs and you don't ride agressively you can get by on stock suspension just fine. Will it handle better w/ stiffer springs? Yeah, but whether or not you spend the money is up to you.
 

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Discussion Starter · #14 ·
kevin_stevens said:
The revelation to me was that, particularly with shock springs, a heavier spring with less preload actually gives a smoother ride over abrupt bumps.
Yeah, I adjusted my suspension per a Race-Tech trained suspension tech. Because I weigh 210lbs, he recommended that both my front and rear preload be maxed out with the stock springs.

It does hold a line better in the corners and feels better overall in the twisties, but regular street riding it gets a little bumpy.
 

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Theres no I in threesome
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The FZ6 is definitely under sprung, but it makes the ride very smooth for long trips. Unfortunately hard braking is flaky at best.
 

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Cheap Bastid
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The maximum preload on a spring should not exceed 15mm. There is usually 12-15 stock, so if you cranked it all the way up, it's way over preloaded.
 

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Well I'm 205 lbs and my 2001 F4i wasn't too bad, however the FZ6 I had was horrible. I mean AWFUL. My RC51 feels harsh and oversprung. So it honestly varies from bike to bike.
 

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Mediocre Strafer
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OreoGaborio said:
The maximum preload on a spring should not exceed 15mm. There is usually 12-15 stock, so if you cranked it all the way up, it's way over preloaded.
Where'd you get that metric? I'd think it would be a percentage of the spring length, not a fixed number.

KeS
 

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Cheap Bastid
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kevin_stevens said:
Where'd you get that metric? I'd think it would be a percentage of the spring length, not a fixed number.

KeS
I got it from Peter Kates, Owner of the GMD Computrack in Boston. Most stock sportbike shocks have roughly the same general measurements when it comes to preload & spring adjustment.

The exact numbers may not be 100% accurate, but the point still remains: If you crank the preload all the way up on any stock shock to achive proper sag for a 200lb rider, it's gonna be way over preloaded and if you put a heavier weight spring on there it will overpowr the stock valving. Your best bet for a properly tuned suspension is an aftermarket rear shock.

But, like I said in an earlier post, if you're just doing easy street riding, you can get away w/ using the stock suspension just fine..... but it'll handle alot better if you go aftermarket.
 
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