I hear you on the flex issue, and it depends on the terrain...the tires are not weightless when you make the shackle longer, and that's all that happens...another 1.5" of swing over the std lift shackle.

You guys act like its a disco for the axle....it just isn't.

If you watch one in action, it is following the terrain...just like a regular shackle swings in/out with the terrain...just because it can swing further doesn't mean the axle fell off and the truck flips over.

So sure, its flexier, and if your terrain doesn't require flex, you can get by with a stiff leaf lift, etc....lift tires when needed, and not worry about articulation.

If you wheel where you need articulation, and understand how to use it, so you don't put yourself in stupid situations (Goes for most wheeling...), its a tool.

Ground clearance is a tool, a tall lift gives clearance...but, at the expense of COG issues, like off camber, etc.

Same with flex.

In reply to Porsche's scenerio... if everything was equal and truck #2 had the revolver fully open then truck #1 would have had it's unweighted tire 1.5 inches off the trail. If this was not the situation then all the other variables were NOT equal.
There is some merit to the fact that a mostly unweighted wheel still contacting the trail (revolver) really isn't doing a lot more than a tire floating an inch off the trail (standard shackle) but I would argue that some pressure on the stuffed tire is transfered to the other tire and does help the LSD work more effectively.
I do not believe that revolvers magicly change the laws of physics or drasticly change weight distribution. If your revolver is opened up then a standard shackle would be floating the tire... either way you should be sure what your line holds for you because your balance may be nearing the limits.

Good Point....but, the unweighted tire scenario is backwards...when drooped, the Revolver's tire is pressed harder to the ground than a conventional shackled rig's.

(NOT unweighted...MORE WEIGHTED)



A simple experiment allows one to measure the weight of the conventional shackled tire on the ground, vs the weight of a revolver shackled tire.

___________

Based on the experimentation I did before mounting revolvers, it appears that, as a conventional shackled leaf suspension is pulled DOWN BY THE WEIGHT OF THE AXLE/TIRE, flexing the leaf arc to droop the tire....there was a change in resistance part way through the cycle.



In other words, from compression/ride height, the weight on the tire was fairly proportional....

...as the leaf was loosened and the tire drooped, the weight on the tire lessened, as the tension of the leaf spring was relaxed...but, at the point where the leaf was exerting ZERO force, the weight of the axle/tire was PULLING the corner down, rather than the leaf PUSHING it down.



So - If you ever changed a shackle, you know there's THAT POINT you NEED when the shackle is unweighted, and the bolt can be slid out, etc....well....THAT'S pretty much the transition point. (Leaf stops pushing down the tire, The axle's now PULLING on it)



This transition point is where the leaf goes from supporting the truck/pushing the tire down onto the earth for traction, to instead progressively unweighting the tire, reducing the force that the tire is pushed down with.



At the limit of leaf support, the shackle (Calmini lift shackle in this case...), swung down, and provided a lot more droop, a few inches...this swinging motion relieved some of the tension pulling the leaf down, and allowed the tire to continue downwards with less resistance than if the leaf alone was responsible for all of the travel.

The amount of shackle swing was the difference between the two ranges...where the support range of the leaf let off, the shackle swing allowed additional droop, until the end of the swing was reached, and once again the leaf was the limiting factor, hanging the tire.

When a conventional shackle swings, its the same unweighted effect on the suspension...the weight of the axle is providing the droop force...)



Doing the same thing with the revolver shackles yielded almost exactly the same scenario.

With the revolver, the leaf went through the exact same compression, ride height and extension cycle...but, when the droop exceeded the leaf's support range, the shackle started to swing, and then, unfold, and it swings and unfolds by the difference between the two ranges...the same as the regular shackle....

When the revolver was unfolding, the tire had more weight on it, as there was less PULLING the tire UP, than did the regular shackled version.

When the tire was fully drooped, the tire would unweight exactly as did the regular shackled version, and the tire would hang.

It hung a bit under 2" lower than the regular shackled version.

On the way down, I had more weight on the tire, and therefore I could expect better traction with the revolver shackle than the regular shackle, once past the transition point, and the same traction above the transition point (BETTER traction drooped, ~ the same otherwise)

____________

So - alot of people forget that their leaves do not push the tire down past that transition point, ....and that the axle weight is what is PULLING the tire down as opposed to the leaf PUSHING it down....

......meaning some traction weight on the tire is lost as the tire progressively fights more and more resistance on the way down in a droop, until that resistance STOPS the droop, stopping further wheel travel.



______________________

I could get almost the same effect as a revolver by simply using a longer lift shackle....I made some rough measurements, and the extra swing of a longer shackle lets the ends of the leaves get closer together/deeper arch....very similar to the effect of the revolver.

I decided to go with the revolver, as while I wanted the travel, I didn't want the associated lift height issues.

The X rides smoother, handles about the same, and the tires go up and down following the terrain...I have almost 2" more travel, with about the same lift I had before, and no downside.

Another thing to consider is we're IFS, not Solid axle. We have to drive the truck with the front. We are more stable on a side hill compared to solid axles. Are front A-arms are what hold use on angles, along with how tall your rear bumpstop is.
My truck will hold at a 42 o angle. I'm also using airshocks in the rear. When on the trail the air flows between the shocks. That way it is always trying to give 50/50 pressure. When one tire is stuffed the air pushes the other tire down. Even with this set-up it is vary stable.
When it's time to get on the highway I seperate the airshocks. So on road they work like a sway bar.

Ramdom Examples of the X not falling over/losing traction due to extra potential wheel travel, if needed...

No. The first rig did not roll as much. Once it got it's leafs maxed out, it didn't roll/tip anymore. The second rig, once it's leafs maxed out, the revolver unloaded when it hit the "bump", and it was too much for the situation, causing it to slam into a tree.

I know both of the guys, both of their rigs, and exactly what they have on both. I helped build 'em, and wheel with them on a regular basis. Their parts are ALL ordered from the exact same company, Rusty's Offroad. Whether you believe an eye witness account or not is not my problem. I was just giving you the story as to what happened, and why I won't put revolvers on my rig, because I've personally witnessed a direct comparison of revolvers vs. regular, and frankly, the extra little bit of travel they give you isn't worth it.

As to how it applies on an IFS rig (careful: my opinion is coming, now) makes them even more worthless. It doesn't do a vehicle any good to have gobs of travel on one axle, and virtually none on the other. Because at the end of the day, it's the axle that has the least amount of travel that'll be the limiting factor on trail, not the one that has the most. When any of the Nissan IFS rigs out there get as much travel out of their IFS as just the stock rear leaf spring provides, then I'd say it's time to increase travel in the rear. Until then, any suspension improvements you do to the back aren't going to make the rig more capable.

TJ:

Not a one of those pictures show a need for a revolver shackle... NONE of those pictures show ANY wheel travel going on in the rear... Those could be STOCK rigs in those situations, and done just as well...

Come to think of it, my wife's Mazda 3 has as much travel as what's showing in those pictures. You got any useful pics to show...? None of those are coming anywhere close to even needing to use the revolvers, much less their failure points...

But, I've got issues with your theoretical statement, earlier:

You're forgetting one very serious component, and the reason why a SOLID axle works better than IFS to begin with.

When one tire droops independent of the other, that tire is being PUSHED down by the OTHER tire. It's a fulcrum & lever. A tire doesn't just drop on a solid axle due to the weight of the axle; that's why IFS rigs have no traction at full droop. When a solid axle drops a tire, it's keeps the same traction, if not increased, because it has a nice long lever arm on a fulcrum PUSHING it down from the other side.

Well then what you just said about the front is the same reason the revolvers work on the back.
I've run the Rubicon both with and without revolvers with no lockers. And there is no way I could have ran the whole trail without the revolvers and no locker.
I don't get you're theory that more travel in back won't help an IFS . So you're saying that it's better to have 2 tires in the air .

Yeah - the whole "unload" thing just is not an issue.

I understand what it looked like, but its not how it works in practice.

They are not spring loaded grasshopper legs...they act just like a longer regular shackle.

If you have ALREADY unweighted the suspension...it doesn't suddenly throw you over....it just leaves the tire on the ground while the truck does what it was going to do anyway.

And the REAR REVOLVERS don't change how the FRONT IFS works...and don't make the truck lean any more than a truck with equivalent longer shackles would.

As you know, a tire hanging in the air means the COG containing rectangle is narrowing...which decreases stability.

The shots show exactly what you said...on the trail, they work just like regular shackles as far as function.

The shot of the X with a buddy kicking the slider on the up hill side is showing that the X is leaned over, just like you could w/o revolvers...but, WITH revolvers, IE: Having the Revolvers did not change my sidehill stability.

The downhill side is fully loaded, as it is with ANY shackle, and the uphill side is mostly unloaded, as it would be with ANY shackle.

The X doesn't fall over from the unweighted revolver "unloading"....because the physics work...and there is no such problem in the field.

The X won't go over unless the COG crosses out of that rectangle....period.

Oye vey...

You can sit and theorize all day about what revolvers will or won't do, and at the end of it all, it won't matter if you can't get the front axle through the obstacle, anyways.

[sidebar: TJ, that xterra on the side-slope in your photo isn't even close to the tipping angle for the rig; hence the reason you didn't see any difference w/ the revolvers.)

The scenario is having a rig in such an extreme angle it lifts a rear tire.

The answer to lifting 1 rear tire is NOT to increase droop travel at that tire (aka, adding revolver shackles).

The ANSWER is to increase droop travel at the OPPOSITE DIAGONAL tire, so the truck frame & body never tips to that degree in the first place.

Until then, anything you do is just going to ben an unsuccessful attempt at throwing money towards a problem you can't fix easily (or cheaply) with an IFS rig. Save your money for something that will help in this situation (like a locker), and leave the revolver shackles to the mall-crawlers.

Mall crawlers don't want revolvers, they don't show, and they don't give enough lift to notice.



And how do you figure I'm changing the weight on the opposite tire anyway?

And its not theory...its truck scales, and lots of little slips of paper with weights printed on it, etc.



I don't think you get it yet...

Maybe you now understand that you have MORE WEIGHT on the drooped tire with the revolver, not less weight...that's a start.

Next Issue -

So far, you are saying that if the truck stays level, and the tire's go up and down independantly, its somehow less stable than a stiff suspension, where the truck goes up and down at each corner, in lock step with the tires?

If I get a flexy leaf that allows my tire to droop a bit lower than the frame bottom, the truck is stable, but if a revolver shackled tire droops the the exact same point, its unstable?

Or are you just against articulation in general, as a flexy suspension is too wishy washy to be safe, and we should just get hummers, lock both ends, and not worry about keeping tires on the ground?



I'd do lockers if I had the time$, trust me. The few extra bucks for the revolvers over the regular shackles wasn't exactly the difference either...not even close.

Hell, I'd do low t-case gears too...overall, before a bunch of other mods btw.

But the time$ thing is there, and real...

All I'm trying to get across is that the revolvers confuse people, much like airplanes on tread mills.

There's also this THING about them, where people talk about them as if they know, and tell others, and the next thing you know, "facts" about revolvers are rampant....like how the tires have zero weight on them when drooped, etc...the exact opposite of a real "fact", etc.

Its like someone who doesn't understand how to measure backspacing "does the math" wrong, and goes around saying the X's OEM BS is 5" instead of 5.5"...and quickly, it appears all over as a new "fact".

Revolvers are ripe for that.

A revolver doesn't toss you over on a side hill anymore than a leaf spring throws you, etc...

I agree about the pics, I have no good pics, sorry...if I'm in a good spot, its typically too hard to get a pic. :rolleyes:

Of course, there's really no such thing as a pic of a side hill that would require revolvers, or any lift shackles...as on a hill, the lower you are, the better.



So - If you're argument is that an X should not have more than 3" of lift, as any more than that will lean over too far, and whack passing trees, and that people should just stay at that height, and save for lockers, fine...then its your opinion about a safe lift height/COG, etc.

We're talking about 2" of travel here....2"...w/o extra lift.

...and, because we did NOT add lift, the OPPOSITE side tire can compress further/lowering the truck more...because if one side is dropping, the other side is being weighted.

That means I'm leaning INTO the side hill on my uphill side more than if I had more lift...as my suspension is MORE compressed on the uphill side when the downhill side is drooped than with more lift.

If I'm side hilled where I'm not drooped, the shackle is folded on the downhill side, and the weight is also supported...so either way, I've been good to go.

If I had too tall a lift, and my COG was across the downhill tire boundry line...I could be talking about a block of wood, or an iron box, etc...I'm going over, simple physics...shackles, axles welded to the frame, whatever, it doesn't matter....your COG crosses that line, you go over.

If the argument is that its only too much travel if from a REVOLVER shackle, then my personal measurements and experience tell me otherwise....travel is travel...gravity pulls the tire down.

There was a video posted here that showed some bozo with a lift w/o flex side hilling, and going over/getting stuck, and providing extreme detail about a lack of judgement, etc....but the LACK of flex flipping him over was the part I was interested in.

When the tire goes up, it tips the truck up, and visa versa...which leads to an easier roll.

So - too little flex can be unstable.

Now, too much flex can be unstable too...a weight on top of a slinky would be tough to control, etc.

So - too little, or too much, flex is the problem.

All we are doing now is agreeing on HOW MUCH flex is not too much, or too little.



A while back, I think it was Carlton and I compared my Revolver/Doubled AAL set up droop, to his new (At the time...) flexy leaf pack/shackle droop...and it was about the same IIRC.

So keep the order of magnitude in mind....its some extra wheel travel, not a catapault.

You still aren't making sense. I have one tire almost in the air, my spare is on top and I still don't see this unloading your talking about

My point is, what good does the extra flex in the rear of a rig do you, if you can't match it in the front? You don't gain any additional useable offroad capability until you address the lack of flex in the front.

If you already had done a SAS, or extreme-long travel setup in the front of your rig, so you've got real flex up front, then by all means, increase the flex you've got in the rear.

The Nissan already comes from the factory with a helluva' lot more flex in the rear than the front. Increasing more in the rear will make for a good photo when you back onto something, but it won't do squat for you on trail until you address the pathetic front flex.

THAT'S my point, TJ. I'm completely against increasing flex in the rear just because you can; if you can't match it in the front, then it's wasted flex that you'll never actually use. Sure, it'll be available, but you'll never be able to get in a situation where it'd make a difference, because your front IFS suspension just plain won't let you get there.

That's because your suspension isn't flexed hardly at all in that picture... The whole rig is turned sideways, but nothing is flexing at the moment...

Yet ANOTHER demonstration of absolutely nothing having to do with the discussion at hand...

And just to post whore a little bit...

JP Online "Lamest 4x4 Products Ever" article

If you're trying to drive an IFS like a solid axle that is you're problem. I use the stability of the IFS to put my truck at what ever angle I need to to keep both front tires on the ground. And I know I have a flexy enough rear to keep pushing. Ask anyone that I led through the Rubicon last year. The revolvers work. I walked through a lot of areas a dual lock X had problems.

By your logic why would anyone want to remove the sway bar. With the sway bar on the rear will still out flex the IFS front. If you can't see how increased flex helps traction we are certainly at an impass.

I don't think anyone ever implied that revolvers were a substitution for a SAS.

I give up on this thread.

Marty, did you drive the Rubicon?

Yes, first time only crawlergears and revolvers, no body damage . The other two times I had a rear locker and revolvers, body damage . Those are just the full runs thorough. I can't count how many times to Spider Lake and back. I also enjoy mountian biking it . Everything I've done to my truck is from what I learned there and some surounding trails.

Porhes, you start to argue one thing, then change your argument, and even prove others arguments at times....

The pictures of TJ and Marty with their Xterra's at angles are compltely relevant to the point of the revolvers "unloading". The shackles are not opening up when put under addttional stress from the vehicles being at an angle. If the shackles were then the body would be leanign more.

ASs to the "it's not worth it argument" - as someone else pointed out then you should be opposed to the removal of a rear sway bar.

And here is a case where having a few inches more flex would have been helpful.

The situation was that the driver needed to back up, and the rear tire was in the air and had no traction, so the X could not go backwards and instead rolled forward into the tree he was trying not to roll forward into (which is not in the picture). Granted, the driver was in the situation because of a bad spotting job, but having that extra droop would have prevented the problem.

I was kidding. You mention you've driven it in almost every post you make.. :rolleyes:

Time to put the transfercase back in the truck The slip-yoke eliminator is done.
So now I can have more rear flex out of my IFS truck
Next year it'll get a front solid axle.

damn y'all are thick...

1) I've personally seen revolvers unload, causing a rig to hit a tree that another rig identically build (except for the revolvers) didn't. Now if someone can tell me how the one that didn't have revolvers defied the laws of physics and missed the tree due to magic, I'm all ears. Until then, the ONLY difference was one had revolvers, one didn't. And the one that did smacked the hell out of a tree on an off-camber situation.

2) For other situations other than off-camber, revolvers are worth about as much as a $3 bill, if you can't match the suspension flex in the front.

For the photo showing the X doing a nose-dive into a tree, when its rear passenger side wasn't on the ground... THIS PROVES MY POINT! If that Xterra had any travel up front other than the pathetic amount available from the IFS, it WOULDN'T have been nose-down in the first place! If the rear tire happened to be on the ground because it had revolvers flexing enough to let it touch, it wouldn't matter, because there wouldn't be any force going to the tire; an open diff in that situation would still have the same problem; no traction to that rear driver's side tire.

So there's two upgrades that could have prevented that X from nosing into a tree:

1) real suspension upfront instead of the non-flexing IFS crap.

2) a rear locker, so if one tire lifts, it doesn't matter.

All a revolver would have done in that situation is give the appearance of traction by letting the tire hang down. It wouldn't have done anything else.

Ugg. I'm through with this. If someone wants a revolver shackle, then please, go spend $150+ for a pair. At the same time, be sure to pick up the other offroading "upgrades" to the Xterra, such as the street "beadlocks", and brushguards. They all do about the same offroad, so you don't want to forget anything.

:p

Wrong - the 2 vehicles also had different drivers. I have seen identical (and I mean perfectly identical with the exception of color) Xterra's with 2 different drivers taking the same line have completely different results because of driver skill.

You seem to conveniently leave that out of the equation in your argument.
Wrong - on multuiple counts.
First of all the only tire in the air is the drivers side rear, all of the other tires are on hard ground. The passenger side tires are all on hard ground. Secondly, the reason the vehicle is pointed nose down is because it is going down an obstacle, both front tires are on hard ground but the vehicle is pointed downhill. The reason the driver needed to back up was because (due to the spotters mistake)the driver had gone (as directed) too far forward to make the turn to clear the tree as it went down the obstacle. That is why the vehicle had to back up. Since the rear wheel in the air was turning, if it had been contacting the ground instead of airborn, that would have added traction and prevented the vehicle from rolling foward.
You contradict yourslef and make my point about changing your argument.
Now you claim that the rear tire wouldn't have had any traction, but the rear axle is a solid axle, and yuou posted this on the previous page about solid axles and why they are better than IFS
So which is it? The rear tire would have the same traction, if not increased - or no traction at all?

You've changed your argument and contradicted yourself. The solid rear axle with the tire drooping cannot have increased traction and no tractyion at the same time, now can it?

[edited]

I erased my response, because like i said before, I'm done with this.

But if you'd like to learn more on how a leaf spring works, and the way it reacts to different forces and in different hangers, do some web searching for real articles, not just messageboard dribble. The type of connection DOES make a difference in how forces are transmitted. For example, there are two degrees of freedom in a revolver shackle, and only 1 degree of freedom in a regular shackle.

Here, I'll get you started in your educational pursuit:

Leaf Suspension modeling