Suspenssion setup on 03/

[rotary13b]

I know that a lot of riders uses stock suspenssion settings and it works fine. However I'm 6'1, 190 pounds and stock setup seems soft. When I get the settings where I like them the ride becomes harsh on the streets.
Did anybody tried different springs,valves,oil?
I heard that by changing to different grade fork oil may help or by raising the level alittle?

[md86]

I've heard of people using a higher viscosity fork oil to firm it up a bit , and some people bolt up different shocks , but I've never done either (yet) . I recently bought a GSXR1100 shock to bolt onto my 93 750 , but it'll be a while before that happens .

[ThAzKat]

The best way to set the bike up for you is Front springs matched to you. You can gohttp://racetech.com/SubMenu.asp?cMenu=17&c=Yes&showPage=street
when there you can find spring rates.

http://www.racetech.com/evalving/SpringRateCalculation/dirtspring.asp?brand=Suzuki&yr=88-04&ml=GSX600F%20Katana&formuse=form1&SpringType=Fork

This is the spring rate they reccomend for someone that weighs 190 pounds.

[rotary13b]

Thanks for the info, I will look it up.

[ThAzKat]

Well when you are as big as me or SweetLou you have to do something. lol

[The CyberPoet]

Re: Suspenssion setup on 03/

I'm 6'1, 190 pounds and stock setup seems soft. When I get the settings where I like them the ride becomes harsh on the streets.

One thing to know is that an '03 Kat (which means it probably has a build date sometime in the second half of '02) is due for replacement fork oil. Fork oil should be changed every two years.

Do you feel the problem is the rear or the front (i.e. - too much sag, or too much dive?). For too much sag, increase the rear spring precompression by a notch and try riding it for a few days. Repeat as necessary. For too much dive, it may just be the need for fresh oil, or you may need to increase the damper rate at the front to three clicks (starting at the left and rotating clockwise; at 190lbs, you don't need the 4th click outside of possibly on the track). Using a heavier oil in the front (15w instead of 10w) will also decrease the front dive a bit, but you will get a harsher ride as a result. If you're used to riding a race-rep bike and push the Kat hard, the cheaper suspension components of the Katana may simply not able to be set to your liking enough, and you may find the need to upgrade components (cartridge emulators, different springs, etc).

Some other thoughts:
Tires play a huge role in suspension systems, and running off-pressure will make the whole bike behave like a wallowy beast. The stock Macadam tires are also pretty poor compared to most of the other offerings on the market (search for tire threads here for more info -- I recommend the Metzeler Z4 and Z6's for all-weather riders, and Pirelli Diablo's for those who rail while riding in primarily dry environments).
A 3 psi drop on your tires can be enough to turn the whole suspension system to crap. For 190lbs, you should be running about 34 psi front and 37 psi rear to retain the optimal tire shape with the Macadams or Dunlops (34.5 psi and 37 psi for Metzeler or Pirelli's at 190 lbs). Always measure the tires cold and inflate to the right pressure before you set out for the day.

Cheers
=-= The CyberPoet

[ThAzKat]

Cyber is right, you should make one adjustment then ride it and see how that is. Only make one adjustment at a time, that way you can figure out what to go to next.

[BearKat]

Cyber is right, you should make one adjustment then ride it and see how that is. Only make one adjustment at a time, that way you can figure out what to go to next.

All of that and a bag of Chips.


I would do all of the before mentioned, and I would suggest to write down where the settings are. That way you can remember what worked and what didn't. I can also speak for the Racetech stuff and the GSXR1100 rear shock, that stuff is great. Gets me around a corner nicely (see ride profile), and I am 5'10" 270 lbs.

[rotary13b]

I tried all of the above allready. I still run the stock Dunlops because the bike has only 6500 km.[33 psi front\36 psi rear] A while back there was a good write up on susspension set up on K.P. I followed it and get the rear perfect to my liking. the problem is the front fork. when at second click it's too soft and it dives alot under hard braking. When in third it's much better however the ride becomes harsh.I work as a car mechanic at a Mazda shop so I did few set-up for our customers where the susspension was firm,vehicle hug the corners great but at the same time it was't harsh. This is what I'm looking for with my Katana.I looked at the Racetech stuff and maybe getting their springs and installing them in the spring. Thanks for all the info,any other suggestions are welcome.

[ThAzKat]

I might get some arguement but it might be the nature of the beast. I plan on going to a Busa frontend for better handling.

[Meikol2]

I think an oil change up front ( I need to do the same) first then upgrade the parts. Adjusting shocks only goes a little ways when you are limited by the springs.

It reminds me of a little pearl of wisdom I received from a Low Rider many years ago. I was looking at suspension options for my car and asked the gentleman if he had cut his springs (bad idea, but cheap), Heated his springs (another bad idea), or replaced them with lowering, progressive rate springs (only proper way to do it at the time). His response was simple.

He said, "suspension? Mexicans don't have suspension!"

I decided that function was most important, and replaced the springs for a fantastic improvement.

UPGRADE.

Unless, like my friend, you only care about the aesthetics.

[OldandReallySlow]

Don't forget to "spring" for some cartridge emulators!!! Well worth the money and they will make your damping rod style forks work soooo much better. Couple that with springs matched to your riding weight and pre-load set properly and you'll think you are on a different bike.

[The CyberPoet]

I tried all of the above allready. I still run the stock Dunlops because the bike has only 6500 km.[33 psi front\36 psi rear] A while back there was a good write up on susspension set up on K.P. I followed it and get the rear perfect to my liking. the problem is the front fork. when at second click it's too soft and it dives alot under hard braking. When in third it's much better however the ride becomes harsh.I work as a car mechanic at a Mazda shop so I did few set-up for our customers where the susspension was firm,vehicle hug the corners great but at the same time it was't harsh. This is what I'm looking for with my Katana.I looked at the Racetech stuff and maybe getting their springs and installing them in the spring. Thanks for all the info,any other suggestions are welcome.

Up that front tire pressure a half psi or a full psi and replace that fork oil, then retest. The OEM fork springs on the 98+ are already progressive rate springs, and at two years old, shouldn't be weakened/worn enough to be bad at a rider weight of 190 lbs. Dive under hard braking isn't uncommon due to the high weight the forks support on a Kat (especially in-conjunction with the weight-transfer action of braking), and I suspect even thicker oil will be unlikely to resolve the amount of dive you're getting to your satisfaction (in which case, only stronger springs will). The cartridge emulators will help quite a bit, but if you do go with them, please put a label to that effect under the fairings or on the inside of the forks somewhere, so future owners of the bike will know the deal with why the damper adjustors don't click into place.

Cheers
=-= The CyberPoet

[ThAzKat]

Cyber is right about thicker oil, I have tried it on a pre98 and it caused unwanted lockup and tire slide.

[rotary13b]

Cyber do u recomend OEM oil or something thicker? How about if I raise the oil level inside the forks lets say between 0.5 to 1 inch? Will that help or the only think it's gonna do is blow the seals?