Yes I know there has been a lot of talk and posts about this topic, but after reading through about 30-50 posts using the search, I have seen some great cages, built on sami's, toyota's, XJ's, etc...
But I never found an answer to the only question I have left to build mine.

I am wondering how strong is an external cage in a hard roll over if there is no crossbracing going through the inside of the vehicle.

My first thought is that if the cage is only a full cage around the outside that it may have weak points on it, but if I add a cross brace through the inside from the floor to the external cage then that will help strenghten the rigidity of the cage in a full roll over.

I only want to buld this cage once, so any input would be greatly appreciated.

Here is an example of what I mean by cross bracing through the inside.

So how much weaker do you think this cage shown below would really be with out the two internal bars?

http://www.patagonia4x4.com.ar/Album/Dan/new8.jpg

Im no engineer but I think that crossbracing would GREATLY increase teh pressure it would take to 'smoosh' the cage.

From what I have seen cages are made stronger by common sense engineering. Your asking the question but you know the answer really. Your just trying to cinvince yourself that you dont need someting when you do if your that worried about it in the first place.

Also somehting that I think you gotta remeber is if it looks 'ok' then it is probably not gonna hold up. Even badass (as far as strength) cages smoosh in a hard roll.

Keep this in mind.

TyTy,
From what I have seen cages are made stronger by common sense engineering. Your asking the question but you know the answer really. Your just trying to cinvince yourself that you dont need someting when you do if your that worried about it in the first place.

Thanks for the reply.

I guess my question is really regarding to the fact that I do not want to cut through my roof at this time.

That is why I am wondering if a exo-cage built with thick enough wall tubing and tied into the body/frame, rock rails, bumpers, etc..
is strong enough with out the internal cross member.

Because if it is then that is the way I would rather go and not cut through at this time.

I only have personally seen wranglers roll so I have no experience in exo rolls.

Thanks
Ken C

U don't necessarily have to cut through the roof. U can make flanges on each side that bolt together and you only have to drill holes through the roof.

J. J.

i have built two exo cages and both work for what they were intended. but they will still flex more than a good triangulated cage. i have floped my rig over three time and it still looks pretty good. if it werent for the exo it would be toast. but it has flexed over and put a crease in the targa. if i would triangulate it, it would have never touched anything. no cross bracing is a trade off for the exo construction. just my 2 cents mike

Originally posted by BRUISER


Here is an example of what I mean by cross bracing through the inside.

So how much weaker do you think this cage shown below would really be with out the two internal bars?

http://www.patagonia4x4.com.ar/Album/Dan/new8.jpg

Is that Dan Starcs 2nd cage in the process of being built???

I have seen his and in my own ponderings I felt there was no way to effectively make an exo work without internal support...
This is what I came up with... (if you look close you can see the dash bars)
http://home.off-road.com/~wanderingwillys/EXO/exo01s.jpg
inside:
http://home.off-road.com/~wanderingwillys/EXO/exo22s.jpg
And the roof attachments:
http://home.off-road.com/~wanderingwillys/EXO/exo25s.jpg

nice work wanderingwillys!!!!!!! that is the way to go IMO. after seeing chris geigers yota pics after the roll with the exo,i am planning something like yours for the luvota.plain exo can save your life,but the thru cab bracing will save the rig(which is what we live for:D ) my .02

gunracer1,
i have built two exo cages and both work for what they were intended. but they will still flex more than a good triangulated cage. i have floped my rig over three time and it still looks pretty good. if it werent for the exo it would be toast.

I was wondering if you might have some pics of your rig w/ the exo on.

Ken C

wanderingwillys ,

Is that Dan Starcs 2nd cage in the process of being built???

I have seen his and in my own ponderings I felt there was no way to effectively make an exo work without internal support...
This is what I came up with... (if you look close you can see the dash bars)

Yes that is Dan's rig.

Part of the reason I asked this question is because I saw your rig on the bad ass XJ post early in the month.

And I must admit you do have one bad ass XJ.

Now a question for you Matt:
How much more weight if you could estimate
did your rig gain by having a full internal and external cage tied together on it.

My other option that I have looked into is building a full internal and then adding rock sliders on the roof so that way I can slide on them along the rocks and trails with out damaging the roof line to bad when I put her over at steep angles into the banks.

Thanks for any info in advance.
Ken C

I estimated by steel yard weights and the amount of scrap left over + the 10 lb spool of wire I pretty much used that it was about 320 lbs of added weight,

The truck scale thought it was closer to 340 - go figure - unfortunately most of that weight is in the worst possible place; the roof , but is sure beats the 18 or 20g sheet that was glued together up there:D

Anyhow the jeep is getting up there in lbs - bigger tires won't help much either :rolleyes:

Matt

Originally posted by BRUISER

My other option that I have looked into is building a full internal and then adding rock sliders on the roof so that way I can slide on them along the rocks and trails with out damaging the roof line to bad when I put her over at steep angles into the banks.

Thanks for any info in advance.
Ken C

I have seen some folks with the factory XJ roof rack do just that and it worked really well, there are 6 nutserts in the roof to work with and then depending on your creativity you can also use the rain gutter to support the deal as well.

There are many ways to skin the cat, just pick one that suits you best and go for it...

Matt