hey danny,

oh my gosh!! check your pressure.  The a$$ clowns at the shop put 60 psi in the set I had swapped this week.  Glad I checked before I put them on. 

Also have you checked your chain?  I know it sounds wierd but when I ran a katana shock I had to run 1.5 inches of slack (measured on sidestand) to keep the suspension from binding.  I'm surprised that there are hundreds of threads about katana shocks but nothing about checking your chain slack to accomidate the change in swingarm geometry.  Before I realized this I would run 1 inch of slack (halfway between recommended) and the bigger bumps would almost throw me out of the seat since the chain was binding and keeping the suspension from using its full travel.  It's almost become my personal mission to tell people about this  

in my case Katana shock = 1.5 inches slack, not .8 to 1.2   Everyone argues with me on this, but most people don't bother to check.

Also, is that tire approved for the rim?  That's pretty wide.  You might not ever be able to get all the way to the edge if it's pinched.

No, I haven't even considered that... when I had everything out of the bike (shocks i mean) the stock one and the katana were practically identical in length, so I never thought anything but the shock itself would need adjustment. Hmmmm...

The tires are approved for the rim width, and a lot of people are running them (this exact brand and size) with great results, otherwise I would've just gone stock... but GSJack and a few others recommend what I'm running.

I'll have to go out and check the slack... That could be the very reason I feel bouncy. What I'll do is put the bike on the stand, and then winch down the rear end to compress the shock and see where things are at under my normal sag and then under say 2-3 inches of compression to see where it binds... if it does at all..?

Time to tinker! 

dont want to sound dumb or thread jack but when you say adjust for about 1 1/2 slack in the chain is that 3/4 up and 3/4 down from center line?

My katana shock was 11.75 inches.  I was surprised that .3 or .4 inches could make such a difference.  If you don't have the tools to rachet it down you can pull the big middle bolt out of the linkage (on the stand, of course).  It will allow you to move the swingarm thru its arc without having to compress the shock.  You will find the chain the tightest when the swingarm is parallel to the ground.  It's not the greatest way since you don't know exactly where the shock would bottom out but it gives you an idea what's going on.  If you already knew that...sorry.

joshr08.  I'm referring to 1.5 measured just like you would measure normally so yes. 

ok thanks just checking thats what i set mine at with the kat 750 rear shock

Okeydokey, here's my findings... chain already has exactly 1.5 inches of slack in it. I was actually thinking of doing what you just said with removing the bolt, but that's for another day.

I also did a tire pressure test and BOTH tires are at 32lbs... the side of the tire, however... says 42lbs cold. So, i think I'm gonna have to go pump about 10lbs of air into them tomorrow and see if that helps at all.

Then we'll come back to the suspension.

Check the tire pressure on the frame tags (my 93 has two, one on the vin plate and one under the seat) and run those pressures and see how things feel.   Note that Suzuki gives differing pressure specs for two up riding.    I have only been riding for a year or so and I'm not concerned with trying to get a knee down at all at this point.   I'm just getting to know my bike and riding in general.

Steering stem is fine.  I didn't fully seat the stem and had play in the retaining hardware.  I fixed that a while back; it's no longer a problem.  Just a bad memory.  

The info in that link probably nails it down for me.  Of course, I've got half a dozen dealership mechs telling me it's unnecessary (and the pressure's perfect) and trying to sell me dual-compound tires...

Good to know about the Avon, Ineedanap.  That definitely helps rule out the tire.  What you mentioned is exactly why I bought it, anyway.  I can trust it for some track time, then?  I've got to find out more about that.  Sounds like I could trust you for some advice, rather than some of the airbags around here more interested in posting animations of fun bags.  
If what I've read about rear pre-load is correct, then too little would result in running wide and/or bottoming.  I'm not bottoming out, and I don't mind running wide for now.  I do need to get it dialed in, but I'm under the impression that higher pre-load causes wheel hop and not the other way around.  What am I missing? 

Quote from: Danny500 on March 18, 2009, 06:31:18 PM
Okeydokey, here's my findings... chain already has exactly 1.5 inches of slack in it. I was actually thinking of doing what you just said with removing the bolt, but that's for another day.

I also did a tire pressure test and BOTH tires are at 32lbs... the side of the tire, however... says 42lbs cold. So, i think I'm gonna have to go pump about 10lbs of air into them tomorrow and see if that helps at all.

Then we'll come back to the suspension.

No! The side of the tire only tells you the max operating pressure, it is not a recommendation, it is a warning. Go with the tire pressure recommended by Suzuki on the sticker under the seat. It is there for a reason.

hey, I like animated fun bags! 

I wouldn't trust me for too much advice.  I just come here to BS with other people who enjoy wrenching and riding.  I chime in when I know something, and ask questions when I don't. 

Anyway to answer your questions...If you're doing your first track day the only requirement is that your bike is safe and well sorted.  As long as they are in good shape those tires will be fine. 

On to part 2.  You can't really just say less preload absolutely does this, more preload absolutely does that.  Setting preload is just that, preload on a spring.  It sets the basic point that the suspension will sit at with the rider aboard.  It does not have any real effect on the spring rate.  A 200lb/inch spring will still be a 200lb/inch spring no matter how many turns you put on the preload adjuster.  The point I was trying on my last post was twofold.  First, set your static sag correctly and your bike will work better.  Second, use your free sag number to determine if you have the correct spring rate.

Try this example...less preload would result in running wide or bottoming, right?  wrong in some cases.

What if the spring rate is too stiff for the rider's weight.  We would have to dial in much LESS preload to get the static sag correct since the spring is stiffer.  Dialing in less preload would not cause bottoming in this case...quite the opposite.  The bike would be VERY STIFF because of a high spring rate.  Also you would find a free sag higher than 5mm because you had to dial in less preload to get the sag.  (It seems backwards but trust me it's right)  We set our static sag correctly and used our free sag number to tell us the spring is too stiff. 

There's more to suspensions than just sag.  Or think of it medically since I know you like that stuff...if you throw bilaterial 14 guage IVs in a hypovolemic hypotensive patient and fill them with 2 liters of 0.9 NS, are you done? 

Set your sag.  Your bike will work better, you will know if you need to upgrade or not,  and if nothing else you will have dialed in one more part of the equation.  And be nicer to everyone else because between everything everyone has posted here someone has the right answer. 

disclaimer: I didn't read every word of this thread

But, I would say a lot might be learned by riding someone else's bike. Could just be your perception, could be that you're doing something wrong, could be something wrong with the bike. Eliminate a big variable and swap bikes with someone for a day. 

FWIW, I've never had the rear of mine do anything but be predictable. IF and only IF I do the same thing with my body! And I don't. I am by far the largest problem with my bike. 

Quote from: ineedanap on March 18, 2009, 10:29:07 PM
I wouldn't trust me for too much advice.  I just come here to BS with other people who enjoy wrenching and riding.  I chime in when I know something, and ask questions when I don't. 

That's exactly why I want your advice. 

I see what you mean about the sag.  I didn't look at it that way, thank you.  Makes a lot of sense.
After I have this solved, I want a variable or progressive rate rear damper.  Do they exist, on the cheap? 


My next question is where to find a safe place to test the system.  I'm wary of another lowside. 
I need an old runway or something that isn't covered in old gravel and potholes.
Guess I'll have to find that myself. 

walmart parking lot or bestbuy they usually have big parking lots that are pretty open on a sunday after noon. also local high school on the weekends usually pretty open for a test of your setup

wladziu, you're really overthinking this. 

Set your sag correctly and go for a ride.  You'll see a difference the minute you get out of your driveway.  You might find your problem has cleared up.  If the problem remains, you can move on to the next theory knowing that you ruled out sag.  If you can't find someone to hold the bike up while you measure, then try turning the preload collar one notch stiffer and see if there is a change.   

You already have a variable and progressive rear damper on your bike right now so don't rush out to find another one. 

Here's examples.  As the suspension moves thru its travel it moves the linkage.  The linkage moves the shock.  The leverage effects between the two will cause a PROGRESSIVE spring rate change based on position.  As a piston in a shock moves thru its travel there will be PROGRESSIVE levels of dampening.  You can VARY the sag with preload.  The list goes on and on.  You can swap to fancier shocks (katana, GSXR, Works) and have more variables to work with but for now you need to figure out your problem.

At this point you have everything you need in front of you to solve this problem.  You have a bike, lots of very good suggestions from the GS community, a theory, and a project (setting sag).  So please try it.  It will take you 5 minutes. 

I'm not trying to sound like an a$$, even though that's what this looks like...although in the time it took to write this I could have set the rear sag and made new spacers to set the front sag too! 

To do the test in leaning go find a Round-a-bout. There is one by a outlet mall next to my friend's house that is never used and I'll just head over there and keep going in circles to see how low I can go. Of course the people who do drive by look at me like I've lost my mind! But, I'm sure I can find it if I keep riding around right?

Mary