Rock rey donkey kick

[fxblflyr]

Has anyone been able to tune out the donkey kick in the rear of a rock rey? I put on proline rear shocks and set it up soft, with 17.5 wt oil and soft springs, but the rear end flies over sharp, small jumps,at almost any speed. Large jumps seem to be fine as the front end gets high enough to keep the rear end down, and it lands smoothly.

 

[JDM74]

The baja rey does the same thing. It has to do with the rebound speed of the rear shocks and the length of the jump. The rear end kicks right as it reaches the lip and causes it to nose dive. Try goosing the throttle on the steeper small jumps right before the lip.

 

[fxblflyr]

Do you think heavier oil or running an extra shock on each side without a spring would help? I figured I needed to keep it a light oil for compression, not sure how to do that and still slow rebound.

 

[JDM74]

You could try a heavier oil, it might help slow the compression but your plushness on the small bumps at high speed is going to suffer. You will not be letting the suspension react fast enough.

Another thing that contributes to it is if you hit the jump fast enough to bottom the suspension the back axle will actually kick the rear up as it hits the bump stops or whatever limits upward travel. If this happens right when the front wheels clear the lip you get a big donkey kick. Stiffer springs might help but small bumps at speed will suffer.

 

[TooOldForThis]

Adding weight to the back should help too, like a spare tire.

The thing about the Rock Rey is the cage doesn't go back very far so I don't think its possible to dial it out completely with weight. The Baja Rey's cage lets you put weight out past the rear axle where it makes a bigger difference.

 

[fxblflyr]

Thanks guys, I will fiddle with it some more. I have one dirt pile in particular that it happens every time, so I can reproduce evidence of changes pretty easily.

 

[BAJAREY2017]

Try heavier oil in the rear to slow down rebound and more preload in the front. If the take off on the jump you’re hitting is shorter then the length of the car it’s going to kick regardless


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[mass-hole]

I just bought a rock Rey and noticed the same thing.

What about running lighter oil in the front? Maybe then the front will “kick” just as much as the rear when launching.

This happens on my mountain bike if I am running to much rebound dampening in the front. I run my rear shock wide open in rebound so that it’s more playful, but if the front fork isn’t set right I’ll come off the jumps tail high which is very unnerving. Of course on my mountain bike, it’s as simple as turning one knob a couple of clicks.

The way I see it, the lighter oil in the front won’t hurt rear bump compliance and may help from bump compliance. It will not help keep from bottoming our with big hits though.

 

[furadi]

Only 1 pack through my Rey so far and I've only jumped it off the angled curb in front of my house. What I've noticed is the donkey kick correlates to how I time my throttle pop. When I time it right it makes a nice clean level jump and the thing will clear the sidewalk lol. I'm running 50wt shock oil front and rear and have the shocks laid down. That being said suspension setup will be an ongoing thing.

Something I thought about is playing with the upper link location on the rear axle. But I'm not certain what that effects.

 

[mOOsE]

solid rear axle has a lot of unsprung weight vs IRS as well. It's harder to tune to avoid the kick, unless it's very soft... which is great for scale, but not necessarily huge RC jumps (think Traxxas UDR)