Hello suspension gurus. Please can you give me some advice?

The last ride I went on I had a bit of a problem that I’m struggling with. It was reasonably rough and rocky terrain, and we were primarily riding faster fire trails as opposed to single track. When doing pop jumps off contour ridges across the trails I found the back end kicking up quite badly, even when I had my weight well back over the rear end. I expect some level of rear kick, even riding across deepish ruts and rock ledges, but I am hoping to decrease it a little.

Now, logic tells me to dial out the compression damping a few clicks, but then I read articles that say newbies often think they need to play with the compression damping setting when it is really need to change the rebound damping. I also read that on rocks, roots, and potholes, it is better to soften compression damping and slow/harden (I presume that means dial in) the rebound damping more than you would on less rough reasonably hardpack terrain.

So, what would you guys recommend? Oh, and background - I am 125kg, have had my racetech springs sorted for my weight (forks and rear) but have the stock valves still. I don’t do any motocross type riding, but I do enjoy jumping contour ridge size jumps. My riding style is not great because I sit a lot rather than squatting, so the rear suspension works quite hard. Hope that helps.

 

You might have too much spring, too much preload, or not enough rebound damping. The easiest to do is the rebound, so add 2-4 clicks at a time, then when it feels like it's better, go back 1-2 until it gets better or worse, then you'll know the perfect setting.

 

zw's comments pretty well sum it up. I see from your bike description that you have Eibach springs. What is your rear spring weight rate? You mention fiddling with compression damping, but honestly the compression damping on both the fork and shock are badly hampered by a main piston that won't flow enough oil under aggressive conditions. If your shock spring is correct for your weight and not overly preloaded, the rebound needs to be increased...the **** turned clockwise. You know you've gone too far when the shock "packs up", which means it doesn't want to extend back into its workable mid-range in a timely manner. Like zw suggested, go clockwise in 2-increment clicks until you get the kick-up off of lips under control. If it then "packs up" and causes some harshness, it may be that you won't get what you want without a revalve. However, it's pretty well known that the stock shock has some harshness under many riding conditions due to that too-small main piston, so sometimes it's hard to discern between what's causing what. Regardless, you can probably get that kick-up under control with some rebound adjustment, and then see if you can live with the effect of any negative performance that might result.

Honestly if you ever ride a revalved KLX or any other bike with good suspension performance, it's one of those deals where you won't want to go back. I did a full Race Tech Gold Valve mod to the fork and shock on my '06 with .44 RT fork springs and an Eibach 6.0 rear spring, and it totally transformed the bike. I weigh 185 pounds with no gear.

 

I should have re-posted the details of my springs from this thread: https://www.kawasakiforums.com/forum...2&postcount=21

"My forks are 0.5kg/mm and the rear is 6.7kg/mm. Moto Pro recommended 0.48 kg/mm on front and 6.4 kg/mm on the back, but I'm happy with the tougher springs I think"

When I had the springs done at the end of June the guys that did it set up my sag correctly, so I assume that means the preload is correct.

I will try and play with teh rebound next time I'm out. Thanks for the advice. I am glad I didn't go out and start screwing around with the compression damping like my "logic" dictated

As for the revalving, it was always in the "perhaps later" bucket when I had the springs done. I couldn't justify the cost of doing springs and valves at the same time, so went with the springs which were the more urgent of the 2. I figure when my fork seals go (not sure what mileage that will be at) I will get a revalve done at the same time as replacing the seals. I can definitely feel the harsh compression spike in the forks you speak of TNC, so I have no doubt you are correct about needing the revalve now - I am no longer a doubting Thomas

 

It's hard to tell how much experience you have so forgive me if you already know to jump, but if you are a beginner, be sure and stay on the throttle all the way as you clear the jump lip. If you let off the throttle even a little when clearing the face, that will cause the front end to dive. You might be mistaking this for a suspension problem. So ... steady throttle and power on all the way through will make for a nice trajectory leaving the jump.

 

No offence taken here at all - I try to stay as open minded as I can on the forums. If someone tells me something I already know I am secure enough to just keep quiet rather than "defend my honour" (so to speak)

I am not a great jumper - my weight and lack of fitness/appropriate strength don't really lend themselves to big jumping. I probably do back off the throttle a little too early as a result, so I will try and take more notice of that next time I head out. If it is indeed a technique thing rather than bike setup, it will probably save me a lot of frustration

But I think I do need to tweak the setting a little anyway, as even when hitting ledge lips and roots on rough terrain I find the back end kicking up a bit.

Just going back to the jumping technique point, and TNC's point about the compression spiking with stock valves, I think it makes sense that I back off a little early to stop over jumping as the jolting landing is a bit off-putting. Better flowing valve would mean freer moving suspension and a more gradual absobtion of the landing shock if/when I do over jump a bit - wouldn't it? Or do I just have to stop being such a princess, take a few spoons of concrete and harden the F*ck up!?

 

LOL!...love the princess and concrete comment.

But really the better valving will make a dramatic difference in both compression and rebound characteristics. The RT Gold Valve kit and probably the other quality revalves completely modify the compression and rebound shim stacks in the rear shock. The front fork revalves only involve the compression stacks, but the fork seems pretty good in the rebound department.

Experience matters, but it's often the quality of the suspension that gives us confidence and allows us not to be the princess.

 

i had the same problem over tree roots etc. with the stock springs, but i am only 70kgs
(stock bike for me had sag spot on!)

softened the rebound damping a little and haven't heard back since! no more biting you in the **** over a ditch

the stock compression damping is set too soft both ends and the rear was bottoming.
harden until action is harsh when riding on rough roads at slow speeds, then soften a little until it is just smooth at slow speeds.

the settings are really touchy and one click can change the whole balance of the bike