exo-cages

i am wanting to put an exo-cage on my xj . i know that with an interior roll cage it will be stronger but if an exo is well designed will it be strong enough to protect my xj by itself or is it a must to have an internal roll cage. thanks for the help and any pics or info would be nice.
thanks

the one big drawback i can see is that it can only really attatch to the bumpers rocker guards and maybe the rain gutter, and then to sheet metal. matt should know, he has an exo that works hehe he tested it out right.

Talk to C-Roc. He has the answers on this topic!

I still think an exo is worthless without interior support members....

sorry, can't help it......

without internal crossbracing the exo would not work as expected... in a side impact (a roll/lean) it will get skewed out of position..... when it comes to an exo without internal components think of a regular car body (of course it's weaker but it's a good parallel) and think about how a rolled sideways body will look.....

Kejtar

I still think an exo is worthless without interior support members....

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Give me some reasons why?



I ask this because after rolling mine 2 3/4 violent barrel rolls, the roof held up better than I could have possibly imagined (windshield was intact, rear hatch window was intact, myself and passenger were un-hurt). I truly believe that a well designed exo that relies on body bracing (by this I mean that the exo would actually bolt to the body) will not only help the overall rigidity of the rig, but would survive multiple rolls without substantial damage (as well as deal with tree and rock "rubs" fairly well. ) Granted, my roof rack, being bolted through the roof, using a spacer, to the interior "sub-frame" or uni-body was largely to blame (or credit) for this, but this just further proves my point...the uni-body is plenty strong (structure over material), but needs some help holding it's shape (exo that is dependant upon using the body for support.)

I actually agree with the interior supports, but don't think that they are mandatory for making a functional exo.

You got lucky... the impact hit it in the right spots... and if you wanna do it... why not do it right ?: )

For 2.75 sideways barrel rolls from the top of "Committed" on Ma Bell, on rocks that blew out the side windows, with no doors???

C'mon...seems to me that this was a good (if un-asked for) test of the XJ's ability to take a hit.

without an interior form, there is no possibility for triangulation.

an exo is certainly better than nothing at all, but if yer gonna do it, DO IT!

at least start with an interior form, and if you want external protection, build outward....

And after you spend all that time/money/effort to "build the inside right", you go out and wheel, and it rolls, and it's STILL totalled and junk, because "everybody" said exo's were junk (which is why you did the inside first). If I had even a modest exo on it, it would not have been totalled. But it was, because it didn't have a straight panel left on it, even though the basic unibody was still OK

I agree with the triangulation...I just don't think this is the first priority.

Save the part that actually has the strength (the form/structure).

Meangreen..
As a distant 3rd party observer let me just say this...

Beezil has forgotten more about the XJ unibody than you or I will ever know. None is aurguing that an exo only cage will not work, they are saying that it would be better, much better, with trianglation. Materials do not have strength, shapes do. (beat you ALL to it) An exo without bracing is just a bigger box, sure, you may have room for that box to cumple before the XJ, but I am not sure i would want to take that chance.

It is your Jeep, and what you do is what you do, but I would take the advise given by Mr. Beezil very seriously.

JMHO

Rev

...the uni-body is plenty strong (structure over material),

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I think I beat you to it. Structure beats material almost every time. But, maybe we should do something about keeping that form, or structure for more than one roll. Look again at the pic I posted...there's NO cage in there, and it's still square. Make no mistake, this was a violent 2 3/4 revolutions roll, from the top of a very large rock face, with lots of rocks to hit on the way down.

Beezil has forgotten more about the XJ unibody than you or I will ever know.

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As much as I respect and admire Beezil's experience and work, I have to point out...did you actually go to my sight and look around? I have spent the last 18 years as a professional mechanic, as well as avid off road enthusiast. I was ASE cert in auto for 10 years (5 as master tech), and am currently an ASE cert master school bus tech. I don't normally tout crap like this (blahblahblah), but I just want you to realize that I'm not just some ninny who just bought his first set of Craftsman tools and decided to play with an XJ.

My "argument" here is that an exo isn't "useless" without the interior re-enforcements. Are interior re-enfocements a good thing? Yes. Do they need to be built in a smart way, so as to triangulate the overall design? Yes. Do you need them before considering an EXO? No. But, I also don't believe in the normal school of thought for exo's (at least as far as XJ's, and other uni-body rigs are concerned). A smaller diameter tubed exo, with lots of exo to body attachment points, would make for a very strong XJ indeed. Add in the interior bracing, or triangulation of strategic points, and you have yourself a winner.

Don't want to come of wrong but a mechanic has next to nothing to do with creating structurally sound constructions whether they be auto body or exo or cage......

You're saying that you rolled multiple times with very little damage..... a good example to prove your theory wrong would be Goatman. All he did was fall over onto his side onto a badly placed rock which has not only dented his side at the roof in, but it skewed his top to the side.....

Also down here in SoCal someone has rolled at our last Jambo (I believe the proper term was the road ran out on him and he went nose down and over IIRC) and his top was all tweaked in all directions..... if that was crossbraced and triangulated... he might have been able to retain his rig... but it wasn't and I think he ended up starting over with a new one...

Kejtar

Add in the interior bracing, or triangulation of strategic points, and you have yourself a winner.

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that is essentially my point.

Hey - you could always get lucky twice in a row, right?


Beezil - PM'd you

Last Month I has the displeasure of recovering Archie and Martha after they rolled on Committed at Mabell as well. I watched the entire debacle from 15 feet above them. Same obstacle as Mean grean.

The truck merely flopped and was a complete write off...and it was a 2001.




IMHO, if this truck had had an interior cage, I feel it would have been repairable (within the ins company's parameters), with just sheetmetal and minor fabwork to get it all pretty again. With just an External? Dunno.

What is my point? Every roll is very different.

I dont have experience with XJ's but do with baja's and yes to get the best performance from nerf, and race bumpers we always tied teh to an internal cage.....the rear bumper to the main support...teh front bumper to the front or windshield support..under the trunk area, the side nerfs to the main support and to the pan.....
If I get the chance to totally finish the MJ before MOAB it will be a combo of tube bed roll cage with exo front, gotta callin some favors with the locals, Ive heped over the last year or so!

wow, thanks for all the good info and pics. i understand what you are all talking about when you say an exo isn't as strong without an internal as it could be with an internal. so if that is the case would you really have to build a full 8 point cage to achieve the triangle bracing that seems to be the key to the success of an exo cage, or could you just brace the exo internally but not have a full cage.
thanks,
KREGG

Meangreen,
I was not trying to infer that you have no knowledge....it is very apparent that you do. I was simply stating a time proven fact based on my own experiances on this board. True, I do not know you, and maybe it was unfair to include you in my assesment of Beezils knowledge. I ment no disrespect.

We cool?

Rev