Steering Problem With Zx6r 636

[Blue636]

Hello, all. I have a 2003 ZX6R and I noticed something about the steering I really hadn't noticed before - why I didn't notice before I really don't know.

 

After riding an EX500, which has been traded for an '03 SV650, I hopped on the ZX6R. In case you're wondering, the ZX6R is going to be a track-only bike which is why I have the SV for the streets and commuting, I don't need suspension upgrades there. Anyhow, I noticed that the ZX6R did not want to turn into corners as well as the SV or EX. It seemed like it was fighting it and I would initially go wider because of it. This was at slow speeds, mind you, and also apply at higher speed but is mostly noticeable at lower speeds. I have the fork preload set at 4 lines showing, assuming I count the very top line so I think it is rather neutral. I have the compression set at 1 click I believe and the rebound set at 6 clicks out. Both forks are set equally and, to my understanding, at rather neutral settings.

 

Here's what's bugging me now - although I knew it wasn't steering properly I didn't notice the problem was coming from one are mostly. After having a friend ride it he said the left fork was the problem but he didn't have a solution. I, too, noticed that it was the left. Whether I was turning right or left it felt like there was resistence coming from the left side, like it was too stiff or it just wouldn't allow the bike to turn at all. My friend said he rode a 954RR which had been dropped and had a bent fork and he said it was exactly what it felt like. The problem is, after a year of ownership, I had never dropped the bike before so I don't think I could possibly have a bent fork... no wheelies or stoppies on this bike either.

 

Essentially, I figured at first it was just the bike and its radical steering geometry. After having a friend test ride even he agreed that the problem wasn't normal. The bike just won't turn in at all! It really fights back but once you're in the turn and you're leaned over it settles and is actually quite stable.

 

This is frustrating, any ideas? Maybe I will ask Balistic to test ride it for me next week if he has the time and see what input he has to give. The bike is not much fun to ride like this.

[paab]

Way too much compression damping? One click out? Where did you come up with that setting? I don't have a 636, but I'm just wondering. Have you changed fork oil? geometry? or done anything to the bike?

[Blue636]

Way too much compression damping?  One click out?  Where did you come up with that setting?  I don't have a 636, but I'm just wondering.  Have you changed fork oil?  geometry?  or done anything to the bike?

 

 

Not one click out, one click from full soft... sorry, should've clarified that. It is practically at full soft with the compression. Essentially, I followed the recommended "neutral" settings by SportRider. They suggest the compression at full soft for the front forks, and I did it all the way to soft and turned it about 1/16" around very lightly to get to that first little click. It shouldn't make a difference, especially the way it is handling right now. Here is a link to what I set it to... http://www.sportrider.com/bikes/146_susp_settings/

 

At any rate, my bike is 100% stock. I've owned it since July of last year and I haven't dropped it or modded it - whether that be performance mods or aesthetic mods.

 

Maybe Will can figure it out when I get the bike to him. I'm wondering if it is because the fork oil is not level on both forks, but I'm not sure.

[RoadRunner]

First thing I would do is service the forks.

Strip them, give them a good clean, fresh oil - make sure it's the same in both forks and then be very particular how you put the front end back together, checking everything as you go along.

[hodge]

Hey there Blu

 

You have a few things working against you on your kaw. It does not sound like there is anything out of the ordinary happenning with it, but rather what you describe is characteristic of how the stock setup will work.

The forks have a stock spring rate of .88 kilo's, so they are probably pretty close for you if your wieht is 150lbs. The big issue is the stock valving of those forks. There is both way too much rebound and compression damping. The result of too much compression damping is that the forks will ride high in the stroke and make turn in very sluggish and push wide.

Even though you are having problems that seem to point to fork set up, in the case of your bike, there is also issues with the shock that are causing you grief. First, the stock spring rate on that shock is about 600lbs. As an example, on Will's race bike, we are running a 500lb spring and he weighs a pound or two more than you ... so you can imagine that with a stiff spring, the back of the bike is held very high, again making the bike push on turn in because the front of the bike is loaded more than it should be. The last problem is that the stock shock has way too much rebound. Try creating up and down motion on your bike, you will find that it is difficult because of the heavy spring and you will also see that the rebound is very slow compared to a setup like Will's. The excessive rebound damping causes the back end to pack in, also contributing to the bike running wide on exit.

Do you know the total and free sag numbers on the shock? What tires are you running?

Basically, with your stock suspension, you probably have about the best setup that you will be able to achieve based on the setup you mentioned following.

If there is any more we can do please let us know.

[Blue636]

Thanks for that reply, hodge. Your description of my problems sound very accurate and I'm sure you're correct in regards to the "best-it-can-be" idea as far as my stock suspension goes. You are also correct when speaking of the stock spring rates of the bike. I suppose it would come as a shock to everyone seeing how low the front fork spring rates are and how ridiculously high the rear spring rate is. Why would Kawasaki do this? Everyone I've spoken to who owns the 2003 model has complained of the harsh suspension and no matter how soft anyone tries to make it the bike is still harsh!

 

As far as the front and rear sag I haven't measured or set them entirely, mostly the rear. I do notice, however, that the rear hardly sags at all when I sit on it. I would guess it doesn't sag more than 12mm! It just doesn't make sense to me.

 

What really made a huge difference was riding the school's bike which was fitted with an Elka shock on the rear. The school's bike handled VERY differently than mine does and it was set up in a way that allowed me to focus on the drills rather than worrying about what the bike will do next. With my bike, I can only ride it so hard because I begin to wonder what it will do mid-corner or upon corner entry.

 

Is there any advice you can offer? I have the stock Bridgestone tire up front and since I got a flat on the rear after 1700 miles (picked up a screw) I replaced it with the BT012SS; somehow I thought it was the OEM tire because it was priced at a discount - $107. I believe the stock rear is the BT012R and I'm not sure what difference it has between the SS beside the compound.

 

All I can say right now is that I do not have much money to put into a suspension but it can also be a gradual process as I'm in no hurry. I can upgrade here and there as my finances permit but I just don't know where to start.

 

Thanks in advance for your advice.

[ZX6R03]

I too have a '03 ZX6R and also noticed the running wide in slower corners but after i got new springs and gold stacks no probs but still noticable very slightly, i belive it might have something to do with the front axel pulling the forks together noy allowing them to compress enough at slower speeds???

[EA6BMECH]

Funny how bikes are different. My ZRX has to have the front end stiff to turn well in a corner. As mentioned that maybe your front end may be too stiff so it doesn't compress in a turn reminds me of hitting the front brake in a turn causing the front end to dive and stand it up. So to me a tight front end turns much better than a loose one. I'm sure some of you would shake your heads at the way I do it, but it works. I would only suggest anything that if your game, number 1, I hope you don't have a worn front tire. Tires are an issue if they're worn IMO when it comes to handling. Give yourself about 1 less line of compression (tighten). Compression (bottom) 5 clicks out, and rebound(top) about 2-3 clicks out. If ya don't like it, no harm done. Will it ride smoother? No, but it should turn in better. One thing I would like to mention is, you were riding an SV and an EX. To me those are sit on top bikes, like mine. Gotta toss them a little differently. I rode a Gixxer 750 and ZX10 after mine on the track. Different bike going to a ZX. I got them both to handle well, but only track experience taught me what to do. Have fun and try a few different things.

PS 012SS's are the stickier ones. Pretty good tires for the most part. Try a fresh set of M-1's. Those in themselves will make a difference....

[senfo]

I'm not sure if this is related but I've had a problem making right hand turns (usually when making a somwhat slow and tight 90 degree turn onto another street) where the front end feels like it just wants to dive or like I just grabbed a hand-full of front brake in the middle of my corner. I'm actually on the gas as it happens so I can't imagine that I'm overloading the front end in any way. I also weigh about 135 lbs and the front end is definitely stiffer than I think it should be.

 

In addition to this, I've definitely noticed that my bike tries to force me to go wide when making slow right-hand turns like was mentioned by Blue636.

[Thor]

I would start by applying the K.I.S.S. principle first (Keep It Simple Stupid) and start with the basics. I don't doubt that you would benefit from suspension upgrades, but I would first ask you, do you remove and mount your own wheels? If you do (and if not, it is a good thing to know to save money on tire mounting), then I would loosen everything up and tighten everything back up. If you loosen your axel from the right side, then I would leave the right axle clamp bolts loose and push the front tire against a wall - don't just use the brake - and get some travel in the forks to properly align the forks(this is done after you properly tighten the axle and the left axle clamp bolts). Then tighten down the right axle clamp bolts. It is possible that something wasn't tightened properly or it just came loose.

 

Then I would check that your forks are an equal amount above or even with the triple clamps (how ever your bike was set up).

 

Now take your bike out for a ride and see if it is still doing it. If it is, go for about a 20 mile ride and then turn your adjusters all the way out per your manual (specifically compression) and then screw them all the way in until snug. Then return them to your original settings. I have had it happen in the past when adjusting a cold suspension that the adjusters act differently than warm. I learned this by trial and error when I had changed setting and I was having a hard time turning one direction vs. the other. When they were warm, one setting was 3/4 of a turn different than when it was cold. The temperature difference was about 30 degrees F.

 

Good luck.

[Blue636]

Thanks for the tip, Thor. I think I might need some time to learn to mount and balance my own tires, maybe I'll do it over the winter break after my semester is over. I have noticed a difference in the way the suspension performs when it is cold, and when it is hot.

 

Senfo, nice to see you hear from the Kawi Forums (I hope I'm not mistaken)! I have also noticed that sometime the bike seems to just want to fall over at a certain angle. I believe this is due to the front tire shape. It never did it before until the front tire started wearing and forming a weird shape. I think new tires will do the trick.

[supernouht]

Keeping with the KISS method here, have you checked your front tire pressure? My bike was impossible to turn till I realised I had a very slow leak in it, you're front tire pressure should be somewhere around 30psi give or take a few.

[vman2957@hotmail.com]

Hi All,

 

I was gald to find this thread don't mean to hijack just figued on the same lines as this thread any insight would be very appreciated.

Sorry if its long winded, and it definitly isn't KISS for me sorry.

 

I have recently returned to the racetrack after quite a while. I have a 03 zx6rr. We dropped a pair of racetech 1.0 springs in the front and I bought a Eibach spring for my weight for the rear.

 

1st race back:

 

The first race back we set the bike at 30mm front and rear as baseline, the bike was slow to turn and even though I was getting full use of my rear the front seemed to be choppering and the wear on my Dunlop D208 front was strange to me , it didnt seem that I was using enough of the edges on both sides . This was confirmed in my last race of the weekend as I kept pushing it and finally it let go at full lean, and almost spit me off the opposite site.I saved it but broke my left footpeg in half with my shin and bent the bracket inwards. We looked at the tire afterwards and you could see where the tire was way to leaned over at the edge of the contact patch.

 

2) Race 2

 

I had a local suspension guy , put in ohlins .95 spring and ohlins valves. Once we mounted the forks to the bike and it was off stand , I pushed on the front end and it seemed squishy to me compared to the RT 1.0 springs in the other forks, but I was willing to give it a shot , because hey ITS OHLINS and the new springs had to be better than stock spaghetti. We set sag at 30 mm front and Rear . 1st corner of first practice I knew I was in for a long weekend, the forks felt like wet noodles and the rear felt like a brick. Not confidence inspiring at all . After pulling in to make some changes (very fast). The bike just felt stiff in the rear and waaay soft on the front. Ad we wasted valuable practice time on head scratching. I was pretty frustrated, my Wrench went scouring the pits for other zx6rr riders to compare there setup, while I sat back in the pits and decided that I was a dork for not getting an aftermarket rear shock. My wrench comes back and tells me all the guys in the paddock have the front dropped through the triples at 10mm minimum and the rear ride height jacked 10 mm off of stock for 15 mm Total (almost to the max). So we went to work and did the same. Sunday we set sag at 30/30 and immediately the bikes front end started behaving, but on the gas, the backend was harsh as they come, the front end had given me hope. Before second round of practice, I neighbor looks at my tire and says "I think you have cold tear" you need to increase your rebound dampening" I cranked it as far as it would go on the stock shock. Went out for round 2 and was able to actually start looking at the track and work on times. back in the pit the tire wear was looking much better. The bike was ride able but far from tearing off the edge confidence inspiring. I went away feeling better , moving forward but still confused, it didn't seem this hard to set up a bike before.

 

3) Heading to next race:

 

I bought a ELKA rear shock off of a fellow racer with a spring suited to my weight, We have mounted the shock and decided since it should be a stiffer stock all through the stroke we were going to bring the ride height back to 10mm even not 15mm. We go to set sag and it seems even with the lack of ride height I have to crank down the preload almost 4 more lines to get 30 mm of sag in the front. The rear with no preload on the spring sits at 33 mm.

 

I am a bit confused at this because you would think that I removed ride height so that would weight the backend more and you would need less preload up front to read desired sag, if this is true then , when I crank the rear to 30 mm it will transfer even more weight up front and then will require me to screw some more into the front as well , which would mean bringing me down to like 2 lines in the front showing. It just seems weird to me that stiffer springs wouldn't need that much preload. And to be honest the front end just seemed to be so settled after I cranked the ride height up , I have never had to do that to a bike before to make it handle. The suspension guy did seemed worried about the Top Out springs in the bike , but he called ohlins and that is what the recommended. And like I said the forks felt fine after the ride height and dropping of the forks.

 

Anyway if you made it to the end of this and can throw anything my way , much appreciated.

 

Thanks,

-Chris V