Donkey Kick/ Ping Pong Effect?

Hey guys, hoping I can get some tips as far as rear suspension goes. I ride off road with a lot of hard pack and sandy whoops that are humongous by some standards. I ride an 07 CRF450X and my suspension is stock. My rear race sag is set at 110mm and I'm at stock comp and rebound settings. On these whoops the rear end wants to kick sideways as I'm trying to skim the tops of the whoops. Basically, I have confused the hell out of myself in trying to fix the problem, so I have gone back to stock settings on the comp and rebound in hopes that someone can tell me which way to go on the comp and rebound. Any help would be appreciated. :bonk: Also, the Owners Manual does not cover this particular problem.

I think its maybe a comp issue (blowing through the stroke as its too soft)

Or its packing cause the spring preload is not right?

How much do you weigh?

imho your sag is to low. Crank it back up to 105 and then play with the rebound. If the rebound is to slow, the shock cannot extend all the way before you hit the next whoop causing packing and deflection.

I think its maybe a comp issue (blowing through the stroke as its too soft)

Or its packing cause the spring preload is not right?

How much do you weigh?

I weigh about 190 without gear. Maybe 200-205 with gear. I am 5'9' tall.

Too much sag. Work with your compression before the rebound. Sand whoops require more compression. Right now, with the amount of sag you have, the shock is already riding low in the stroke, so it's packing. Hondacrf05 is correct in that your shock is not recovering fast enough for the next bump, but it's because it's packing since you've got too much sag and probably not enough compression.

I weigh about 190 without gear. Maybe 200-205 with gear. I am 5'9' tall.

Are your springs stock? Also, don't be surprised to find that your riding gear can add 20-30 pounds.

You need stiffer springs, if you haven't done that already.

imho your sag is to low. Crank it back up to 105 and then play with the rebound. If the rebound is to "SLOW", the shock cannot extend all the way before you hit the next whoop causing packing and deflection.

I set the sag at 110mm mainly because I was told that that is best for off road. Helps with straight line stability and all. By "SLOW", do you mean too hard, or too soft? I have read the Too Tech Set Up Instructions and the MX Tech guide and they seem to contradict each other. One says to go harder on the rebound and one says to go softer on the rebound. This is where the confusion comes into play. In about January or February, I will have my suspension sent off to get it set up for me. But until I have the money, Unfortunately, I am stuck with stock suspension. I just have to find the best setting that I can for now. Thanks for the help guys, keep the ideas coming please.

Are your springs stock? Also, don't be surprised to find that your riding gear can add 20-30 pounds.

You need stiffer springs, if you haven't done that already.

Yea, there stock, for now anyway. Okay, so come back in on my sag and work with the compression first. Is that correct?

Too much sag. Work with your compression before the rebound. Sand whoops require more compression. Right now, with the amount of sag you have, the shock is already riding low in the stroke, so it's packing. Hondacrf05 is correct in that your shock is not recovering fast enough for the next bump, but it's because it's packing since you've got too much sag and probably not enough compression.

RKS1, by more compression, do you mean harder compression? Sorry, the terminology sometimes gets me.

RKS1, by more compression, do you mean harder compression? Sorry, the terminology sometimes gets me.

CORRECT! MORE = Turn it in, make it stiffer, SLOW IT DOWN....however you want to say it. I know what you mean, it can get confusing!

Bottom line - we want to slow the compression stroke down. And to do that you turn the adjuster screw clock-wise.

110mm on a CRF frame it too much. I understand what you mean about the stability factor, but at 110mm it must turn about as good as a Greyhound bus! 105mm should be a good "compromise" between the stability you need and still be able to turn.

As far as rebound, my personal philosophy is you want it "just" fast enough so the shock can react in time to the next bump, without being too loose that it wants to kick - or too slow that it packs and causes the bike to go sideways. You can probably run yours at 8-10 clicks out to start and then fine tune from there.

:bonk:

CORRECT! MORE = Turn it in, make it stiffer, SLOW IT DOWN....however you want to say it. I know what you mean, it can get confusing!

Bottom line - we want to slow the compression stroke down. And to do that you turn the adjuster screw clock-wise.

110mm on a CRF frame it too much. I understand what you mean about the stability factor, but at 110mm it must turn about as good as a Greyhound bus! 105mm should be a good "compromise" between the stability you need and still be able to turn.

As far as rebound, my personal philosophy is you want it "just" fast enough so the shock can react in time to the next bump, without being too loose that it wants to kick - or too slow that it packs and causes the bike to go sideways. You can probably run yours at 8-10 clicks out to start and then fine tune from there.

:bonk:

Okay, I get ya this time. I am running 11 out on Compression and 8 out on Rebound and it seemed to be better. Thanks for the advise. Now I can fine tune a little if I need to. I may see about sending my suspension to you in February!:bonk: Oh, PS: You are right about the Greyhound Bus!

For stability, I keep two chains. One cut at the stock length and one cut one link longer. The farther back you move the rear wheel the more stable the bike becomes without upsetting the balance front to back. It will turn slightly slower at turn in, but its going to if you run your sag that far down anyway. I like to comprimise when I make adjustments. Meaning, if I feel one end is to soft or hard I will soften the one I feel is to hard one click and stiffen the oposite end one click. That way the you don't change the way the bike handles any where else on the track but in a sence, you just softened the stiff end two clicks and the balence overall still feels the same. I only do it that way if there is one area or obsticle on the track giving me problems. If you are having problems everywhere, go back to a base setting and start over.

Bye the way, I would recamend rsk1 for your service. If he helps us this much for free, imagine what he would do if you paid him.

If youre a C ormaybe B rider you should be able to get a pretty good setup with stock componets.I'v found softening up the rebound and then softening up the compressione(spelling) helped me.I haven't had all that great of luck by just haveing my suspension done.Find someone who will ask Questions and listen to what you tell them,be honest with your'e skill level.You wil still need some tweeking but once there ,very confidece inspiring.Best of luck:thumbsup:

Bye the way, I would recamend rsk1 for your service. If he helps us this much for free, imagine what he would do if you paid him.

You think I get paid for ANY of this!? :bonk:

(Just kidding, Jer!) :bonk:

Thanks for the props! And great suggestion on the chain length idea!

:bonk:

i always found that my 07 450x was a better alround handeling bike with lots of sag , last time i checked it , it was at 115mm and then i added more and i found it stopped the front wheel washing out all the time , when i went back to around 100mm sag it was horrible , however it was always a little harsh where i liked it and i always ended up with my comp clickers close to full hard setting. a lowering link aswell as a proper revalve should work wonders for it .

ok i didnt read throught the first two pages but if your sag is set up correctly then leave it alone. and if your back end wants to slide out from under you that means there is too much compression dampering and it has no where else to go, so back the clicker outand test it till it stops. it it starts to pack down maybe clickin a compression and out some rebound.

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