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PRACTICAL roll protection devices

92xjsp

NAXJA Forum User
Well, the gyroscope and weight accelerator systems drove me off that other thread :)

I still want to explore the idea of what practical steps you can take to deal with rollover risk. I’ll admit I’m a web wheeler – I’ve had a stock XJ for 6 years and a stock YJ 6 years before that, and I wheeled them both pretty aggressively for stock, but that’s nothing compared to what lots of you guys have done, and the only times I’ve come close to rolling were purely accidental. So I’d like to benefit from your advice.

But even though I’m a newbie, there are some things I just don’t buy, like (1) there’s nothing you can do about rollovers, you just have to accept it when it happens, or (2) that you guys are taking it “right up to the edge” but that you’ve only rolled 3 times or 5 times or whatever. I canoe a lot and I know some blowhards who’ll say “I take my canoe to the edge all the time and I’ve only swum (slang for capsizing) 2 times in my life!” Well, I’m not a newbie to canoeing so I know you can’t possibly even know where the edge is unless you flip 20 times a year. I suspect the same applies to wheeling.

Now, even though I’m stock right now, I’m planning my first buildup (have been for 2 years) as soon the 92 XJ quits being my daily driver, which should happen within 6 months now. Rollovers have been in my mind as a performance limiting factor for a long time now, so there are certain things I’m planning as part of the buildup to keep a low COG: (1) minimal lift, thinking 2 inches right now, and using fender trimming to fit 32 inch tires (2) lots of armor low and mounting positions for tools, hi-lift, spare tire etc low and central (3) bs’d wheels for a couple inches wider track.

All that should help, but even then I want to take it to the real edge, and so I’m working on several ideas to help cope with rollovers. Now, I know I won’t prevent them all so I’m ready to take a couple when all the systems fail. But the idea is to be able to test the edge, the real edge, to go past the roll point dozens of times, and to be able to recover from all but one or two of them. From my web-wheeling, I’ve seen a number of slow-mo rolls on video that look like they would have been easy to prevent. So starting there, I get the ideas of a low brace bar, a high side countervailing weight and a series of locking plasma rope reels on the cage for anchors. All of these seem doable and helpful in some situations. I’ve got some detailed thoughts on how to deploy these and I’ll add that to the thread later if we can get a constructive dialog going.

I am pretty much convinced the systems have to be all manual, for the driver to deploy as his experience and judgment dictates, either with buttons on the dash or by calling on spotters to do something.

Also, I think pre-calculated roll angles are next to worthless and the only possible working gauge is one that measures suspension load at each wheel – but I don’t have the vaguest idea how to do this at a reasonable cost – some kind of scale. Once you get this measurement, then you’ll have to go do some real world rolls (using your low brace bars to catch yourself) to see how gauge measurements relate to roll risk.

Also, the cage is a related point – most cages, as I understand it, are constructed in such a way that they can only handle one roll (say 360 degrees down a rock slope) and still be safe. Meaning, you have to rebuild the cage after every roll. To build one that could withstand multiple rolls would be prohibitively heavy and costly, I’ve been told. That’s a real drag, I hope they’re wrong. I want one I can roll once or twice today, then drive back to camp, then keep going tomorrow and roll it again.

Any thoughts? Flames welcome too, as always, just try to mix in some facts.
 
92xjsp said:
So starting there, I get the ideas of a low brace bar, a high side countervailing weight and a series of locking plasma rope reels on the cage for anchors. All of these seem doable and helpful in some situations. I’ve got some detailed thoughts on how to deploy these...

Read: high Lift, towpoints, straps, Not wheeling alone.
 
yep, I agree.

a well designed and fabricated cage WITH TRIANGULATION.

keep the CG low.

big lifts add the possibility of rollover.

wide trackwidth helps.

I personally have 7" of lift and 37" tires, and can get WAAAY off-camber.

balanced suspensions, avoid stiff rear.

no crap on the roofline. tires axle shafts and high lifts belong LOW.

picking lines, good spotting, help from your friends, tether lines to your rollcage during narly spots, counter balancing by dudes with beerguts, no paranoia, no fear to drive out of it.

lastly, experience and driving skill.

web wheeling is the best way to avoid a roll.
 
B, thanks for the help with the sig :D

A well thought out cage with the proper materials can take many decent rolls.

A few years back I had been trying to come up with a way to transfer weight and all that crap, but it just won't work. It adds useless weight and takes away much desired cargo room. There is no way that you can actually drive and try to push buttons or pull ropes or whatever and still keep from rolling. The best remedy to preventing a roll once you are at that point is reaction time with your gas pedal and gear selector.
 
1. Most important, competant driver who knows his/her vehicle (not under the influence).

2. Good spotter, who you have worked with for a long enough period of time to trust and respect.

3. Low CG.

4. Practice. You do not need to roll a vehicle to understand what you need to avoid. You do need experience to pick lines that are the the best for you and your vehicle.

5. A well designed and built roll cage, just in case.


Do not ever under estimate a good driver or driver/spotter combo. I have seen a ZJ on 35's (driven by a woman) that was a pristine DD take on beater full size trucks on 40+'s in rocks that would eat either for lunch. she completed the course and many, many, many other trucks bearly got started. a driver who knows their vehicle is a very usefull tool.

Michael
 
There's another factor that renders any system of movable counterweights impractical -- physics.

Remember the old "For every action there's an equal and opposite reaction" rule? That applies here.

Let's say you have a massive counterweight on a lateral track in the center of the vehicle. You start to lean too far to the left, so your deployment mechanism (air, hydraulic, gunpowder, doesn't matter what) fires the weight off to the right to balance the chassis. If you're at or near the limit when it fires, the reaction -- the "kick," the recoil -- will push the vehicle in the opposite direction (the direction you DON'T want it to go). The heavier the weight, the greater the reaction.

The net result is that such a device would necessarily need to be deployed before you get to the point where it's needed. And if you deploy it before you need it, then virtually by definition you are not taking it to the edge.

BTW -- I don't agree with your view on what taking it to the edge means. Professional race drivers pretty much have to drive at the edge in every race to be competitive. They crash unassisted once in awhile, but by your definition every racer would have to take himself out once during every event to be considered driving at the edge.
 
2xtreme said:
You do not need to roll a vehicle to understand what you need to avoid.

(Don't mean to pick on you especially, Michael, everybody's saying this same thing only you said it most directly.)

This is what I disagree with most of what all you experienced guys are saying, and it’s what made me speak up on that other thread. You won’t admit that you’re giving up any performance because of the risk of rolling the vehicle. This is so wrong that I’m kind of at a loss for how to argue against it. Ya’ll ever been with or seen that west coast guy Camo wheel? I haven’t, except on videos, but I gather he knows how to get on the edge. I’ve seen photos where he was almost vertical, it was amazing. Ask him how many times he’s rolled. I think it was about 50 the last time I heard. And I guarantee you he’ll have a better feel for how far he can go than somebody who’s never rolled.

Eagle, race car drivers don't race *on* the edge because going over the edge means you die. They race near the edge (too near for me even on amateur tracks - those guys are crazy). If they could crash with few bad consequences, say a 20-second penalty, no death, no car damage, and then be back in the race, you'd see them race *on* the edge *and they'd be even faster than they are today*. And that's the idea with the roll. If you can make the roll not be a life-or-death sort of thing, you can pick up a performance boost by going from near the edge to on the edge.

So, first step is to admit a performance give-up – maybe small, maybe not, but still a give-up. Once you admit that, you can work on ways to let you get back some of that performance.

Actually, there’s nothing magical, as far as I know. Shooting weights and gyros and all that stuff don’t sound like it would work for all the reasons mentioned. But I do thinking there are some little things that can be done to make what you already do to deal with gnarly situations easier. Kick stands that you deploy before the obstacle (or that your spotter pulls out as a last resort), multiple plasma lines that one man can deploy and control from the drivers seat, levered handholds for the guys with the good beer bellies to make the best use of their weight, etc.
 
Even if all those gismos you are describing would work, they would just make your rig a very dangerous thing to be around. The last thing I want is my wife (my spotter) to run up to my XJ as it is rolling over (or even when it is close) to fold out some sort of kickstand, or pull on some sort of pully, or to have all these ropes and pulleys and powered mechanical devices on, in, or around my truck waiting for my kids or families fingures to get stuck or crushed in. Even jumping on the high side of the vehicle, though common practice, is not a very smart idea.

You're best bet is to do as the pro's, have a good roll cage and a long rope connected to it when needed for the spotter to pull on. Otherwise you're likely placing people in more danger than they were before.

My 0.02.
 
92xjsp said:
Eagle, race car drivers don't race *on* the edge because going over the edge means you die. They race near the edge (too near for me even on amateur tracks - those guys are crazy). If they could crash with few bad consequences, say a 20-second penalty, no death, no car damage, and then be back in the race, you'd see them race *on* the edge *and they'd be even faster than they are today*. And that's the idea with the roll. If you can make the roll not be a life-or-death sort of thing, you can pick up a performance boost by going from near the edge to on the edge.

:bs:

Sorry. I don't buy it. I don't see that a competitive race car driver can afford to be any farther away from "the edge" than your California wheeler guy. Whether racing on a track or doing extreme wheeling/rockcrawling, the goal is to be that close to the edge without going over the edge. I think you're playing with semantics.

Tell Jeff Gordon he's not driving at the edge and he'll punch out your lights.
 
You're both right.

Ask Jeff Gordon how many times he's crashed and it will be in the hundreds I'm sure. But now he is a professional race car driver and with all that experience he is able to race on the edge and not go over, unless he makes a mistake. Ask any professional rockcrawler and I'm sure they have rolled many many times as well.

Plus the comparison isn't a very good one. A recreational wheeler may roll more not because of the life and death difference, but because of the difference in goals. A race car driver isn't going to win races, and therefore make any money if he drives so fast he is always crashing. Same goes for a professional rock crawler. They want to go as fast as they can without rolling, or they lose. I bet that pro-rockcrawlers roll all the time in practice though (to the extent they can afford repairs anyways).
 
Eagle said:
:bs:

Sorry. I don't buy it. I don't see that a competitive race car driver can afford to be any farther away from "the edge" than your California wheeler guy. Whether racing on a track or doing extreme wheeling/rockcrawling, the goal is to be that close to the edge without going over the edge. I think you're playing with semantics.

Tell Jeff Gordon he's not driving at the edge and he'll punch out your lights.


Semantics? yes.

Mark Donahue was interviewed in the late 60's and offered a theory that the way to win races was not to run the 101%, on the ragged edge of the handling limit in the dangerous fast turns, but to consistently run the safe side of the 99% edge all the time (even in the slower safe turns). His reasoning was to fill the entire "area under the curve" envelope for the entire track. He went on to review how they tested the cars safe limits on skid pads and modeled the course on paper with the target speeds for each braking marker and corner. Then testing at 90% and faster. It appeared to work well (until equipment failure during testing ended his life).

The deep lesson to this story is there is no safety in technology, or scientific method, and that avoidance is the only sure way to eliminate risk.
 
Ed A. Stevens said:
Mark Donahue was interviewed in the late 60's and offered a theory that the way to win races was not to run the 101%, on the ragged edge of the handling limit in the dangerous fast turns, but to consistently run the safe side of the 99% edge all the time (even in the slower safe turns). His reasoning was to fill the entire "area under the curve" envelope for the entire track. He went on to review how they tested the cars safe limits on skid pads and modeled the course on paper with the target speeds for each braking marker and corner. Then testing at 90% and faster. It appeared to work well (until equipment failure during testing ended his life).

Mark revolutionized race car driving, especially on road courses. He's the guy who articulated why it doesn't make sense to go through corners balls-to-the-wall if it means your exit speed is down, because the "area under the curve" is maximized by going as fast as possible on the longest straight on the track. To do that, he theorized (correctly) that if you reduce your corner entry speed in order to maximize your corner exit speed, you're ahead in the long run.
 
92xjsp said:
(Don't mean to pick on you especially, Michael, everybody's saying this same thing only you said it most directly.)

This is what I disagree with most of what all you experienced guys are saying, and it’s what made me speak up on that other thread. You won’t admit that you’re giving up any performance because of the risk of rolling the vehicle. This is so wrong that I’m kind of at a loss for how to argue against it.

No offense taken!!

The best people I have wheeled with have NEVER rolled a vehicle. They are the people who can make it look easy to tackle a obstacle that most others in the same vehicle or even more capable vehicles could do. They do it safely and they THINK before they do something. I still think that a competent driver is key, they have the experience to pick a line, they have the experience to know where to put a safety line and when. And they can do all of this without rolling.

I do agree with you that you might be more capable of understanding what it takes to roll or avoid a roll after you have been in one, but for the normal non professional wheeler I do not agree that you have to roll to become a expert.

Racing of anykind, any sport you have to be as close to the "edge" as possible without going over. Those who go "over" the edge usually are not able to compete regularly due to injury, money, etc. All professional athletes and drivers try to get as close to the edge as possible without going over, they do not practice going over the edge regularly until they have enough experience to tackle it without going over the edge.

Again, just my thoughts.
Michael
 
Discovered a long time ago, I have small talent for driving. Everything from 200 MPH motorcycles, through off road, to heavy equipement. Never was crazy enough to be competative. Heard more than one driver say, you got to finish the race to have a chance at winning. I´ve gotten old, along the way, buried many who just didn´t have the talent, instincts, the incompetant or the unlucky.
Don´t have to hang, from the edge of a cliff, to figure out if you got it, training will only take you so far. Split second instinct, if your lucky, you´ll figure out if you have it or not, before you go too far or to fast. if you don´t, you probably have other talents, live to cultivate them, drive within your capabilities.
Learning on a platform with sway bars and moderate lift, makes sense before graduating, to high lift and max articulation. many of the rollovers, I´ve seen, reminded me of a tall building falling over or a slinky spring falling over, body roll.
Every year, a few guys eat it on this board or that, rarley with a stock vehicle. I´ve heard guys wanting to remove there trac-bars for articulation, Jeeeez.
I used to free climb, never fallen, desert and road race, never flipped, high speed bike (everyday for decades over 130 MPH) never had a high speed wreck. I´d be more likely, to take my advice from somebody who has rarley, if ever rolled one. I´ll stick with a low center of CG, skid pans and sway bars or limit straps. Two different kinds of adrenelin rush, the rush of exhilaration or the rush of panic.
I´d still like to figure out a way to brace the windshield post, without a full rool cage, something tucked in and mostly hidden.
Watched my brother do a 15er barrel roll down a hill, I passed on. The centrifigal force pulled his seat belt stud out of the floor, fractured vertibra and internal injuries, door popped open, he flew out, car rolled over him. High horsepower motor, sheared the flywheel bolts, just at the top of the hill climb. Funny, just before he rolled it, I tried to get him to tie the doors shut and roll down the windows. He looked at me like I was nuts. Tieing the doors shut, on an XJ, could help with the windshield crush on a XJ rollover. The doors pop open some and allows the windsheild frame to crush between the doors. I sure would like to figure out a way to brace the windshield post. Maybe a partial EXO disguised as a roof rack?
 
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