Stock shock bucking

[rtmozingo]

Hey everyone, I was wondering who else has noticed and/or experienced bucking (ie rebound liftoff) after hitting rougher stuff in their stock gen 2. My first ever takeoff I experienced it, and while it was not problematic in the slightest, my understanding is that usually this indicates some tuning needs to be done. Obviously these shocks have to be split 50/50, so is this just a byproduct of their dual role, and if so, is there any concern other than temporary loss of control?

If you want a good video of what I'm talking about, watch the last bit of the RR/Cobb video:

 

[Loufish]

I agree...the factory valving is a compromise trying to please the most amount of people but of course not everyone.
I'd love to find someone (who knows what they're doing) add some more rebound in the bump zone, that would still keep the rebound light in the normal ride zone...
That's what I see and feel....

 

[stephenisROGUE]

Don't forget difference of unsprung weight, in wheels and tires... Also changing the default or ride height changes characteristics of the stock motion ranges.


That video, they are literally driving it into the ground.

 

[nikhsub1]

The OEM rear springs suck. That is the problem...

 

[Loufish]

Replaced my rear springs with a set of +3 Deavers and SVC 2.0 Fox bump kit and the back end behaves pretty good with the stock valving...

 

[rtmozingo]

The OEM rear springs suck. That is the problem...

And yet the rear isn't bottoming out - it is the front. I think the compression is too low up front, causing bucking on the hard hits. But stiffening it up means worse ride the rest of the time.

 

[Loufish]

But stiffening it up means worse ride the rest of the time.

If you just add stiffer springs, yes and of course stiffer springs usually means you need more rebound to control them...
Again finding a source that knows our shocks and how to "fix" them is the key because as By Pass shocks you can get the stock soft ride in the normal ride zone and add compression/rebound in the deeper part of the shock compression travel...

 

[rtmozingo]

If you just add stiffer springs, yes and of course stiffer springs usually means you need more rebound to control them...
Again finding a source that knows our shocks and how to "fix" them is the key because as By Pass shocks you can get the stock soft ride in the normal ride zone and add compression/rebound in the deeper part of the shock compression travel...

Without upgrading shocks, you cannot keep the softer ride if you revalve. I asked a very experienced shop about this a year or so ago just because I was curious. That's part of the reason the Live Valve shocks are so ingenious - you get the tuning capability of aftermarket clickers but in automatic form. A live valve 3.0 external shock would be ideal - and indeed, that's what I'm waiting for.

 

[Loufish]

Without upgrading shocks, you cannot keep the softer ride if you revalve. I asked a very experienced shop about this a year or so ago just because I was curious. That's part of the reason the Live Valve shocks are so ingenious

I dis-agree...these are like external tube by-pass shocks (although the mechanism is different) in that you can re-valve the piston stack, and open or close the by-pass ports to get the ride you want in the normal ride zone..In our case stiffening up say the compression stack would result in a stiffer ride thru out the entire shock stroke, but opening up the internal by-pass ports would soften up the ride in that zone...

Mind you this is somewhat theoretical because unlike an external tube you can adjust, our by-pass has to be accomplished by opening up the internal ports and without some experience you don't yet know how much bigger to drill out those ports to achieve the desired by-pass...

 

[rtmozingo]

Well Cobb's response in the engine forum explains some of the video:

"The suspension was completely stock. It took a beating over a long, long day and held up fairly well. The shocks eventually began overheating and then eventually all failed. After a day of cooling the shock behavior started working more normally but they could all probably use a rebuild. We haven't jumped it since the video so it's tough to say how far gone they are. We're looking at an aftermarket system now but aren't quite sure what we'll end up going with."

I've run all day in Texas heat without my shocks showing signs of overheating, so I either was oblivious, not running hard enough, or these guys were hammering it hard all freaking day. Not sure what to think of that.