Roll Cage Failures

[gt1guy]

I wanted to add support to my A-pillar, but didn't want to make getting in and out a pain, because this is will also be street driven.

My thinking is that the A is one of the longest (unsupported) spans, that also has a couple bends in it. By unsupported, I mean in-plane support.

This doesn't really interfere with getting in and out. Doesn't interfere with seeing the mirrors or vision in any way. But it does act like a gigantic in-plane gusset for the A-pillar. You can see how the bends in the A are now fully supported.

 

[Toreadorranger]

I wanted to add support to my A-pillar, but didn't want to make getting in and out a pain, because this is will also be street driven.

My thinking is that the A is one of the longest (unsupported) spans, that also has a couple bends in it. By unsupported, I mean in-plane support.
This doesn't really interfere with getting in and out. Doesn't interfere with seeing the mirrors or vision in any way. But it does act like a gigantic in-plane gusset for the A-pillar. You can see how the bends in the A are now fully supported.

Working within the limitations of a street driven rig this isn't that bad. It would be a little more ideal if It was more vertical for supporting the top of the A pillar. But this is a great compromise for a street driven rig that you don't want to dukes of hazard in and out of.

 

[desertPOS]

I always think of this at KOH a few years back - looks like rock placement contributed to kinking some tube, but also seems like it was lacking a lot of gussets that it should have had. Look how close the b pillar is to his head/neck. Seems like proper gusseting could have made a huge difference!

 

[MochaMike]

With some slight bends you could. It wouldn't be ideal in terms of absolute strength but it would still be a big improvement IMO.

Question: What are your shoulder straps on the harness attached to now?

If you look at the pictures without the seats, you can see the lower spreader that goes between the B pillars. I added an 18" of 1.5" wide 3/16" plate going to the center of the seats.
Not really a great idea really. Hence why I want to do another spreader.

In all honesty, 90% of the time I only wheel with lap belts. I use the shoulder harnesses when I'm on dirt roads (top speeds of 20-30mph, even on pavement), or really technical/hard sections with the chance of rolling.

 

[92 Green YJ]

I always think of this at KOH a few years back - looks like rock placement contributed to kinking some tube, but also seems like it was lacking a lot of gussets that it should have had. Look how close the b pillar is to his head/neck. Seems like proper gusseting could have made a huge difference!

Wow. That B pillar bar is scary looking. I can’t believe it crunches down like that. I agree a simple gusset between that B pillar and the forward spreader to the A would have helped prevent the A from folding like that. I do wonder if it would have made any difference on the B crushing down like that.

its kind of hard to tell if it crushed down from the top of if it took a side hit as far as what actually caused that B pillar carnage.

 

[desertPOS]

Wow. That B pillar bar is scary looking. I can’t believe it crunches down like that. I agree a simple gusset between that B pillar and the forward spreader to the A would have helped prevent the A from folding like that. I do wonder if it would have made any difference on the B crushing down like that.

its kind of hard to tell if it crushed down from the top of if it took a side hit as far as what actually caused that B pillar carnage.

It's just a very poor design for multiple reasons, in my opinion - I'm surprised it even passed tech, honestly...

 

[92 Green YJ]

It's just a very poor design for multiple reasons, in my opinion - I'm surprised it even passed tech, honestly...

Agreed. Zooming in and looking even closer, that B pillar tube doesn’t even go to the floor from the looks of it. It looks like it’s welded to a plate that was attached to the top of the sheet metal square pillar between the doors. Hard to tell for sure in the pics though.

 

[bdkw1]

It's just a very poor design for multiple reasons, in my opinion - I'm surprised it even passed tech, honestly...

No shit, where's the diagonal for the B pillar hoop? Or any diagonals. Would not pass SCORE or BITD.

 

[Wendle]

I find B pillar design to be the hardest thing with laying out a cage.

I usually try to get the B pillar into a position where you can't bang your head into it on random little bounces, but that leaves the shoulder bolster of the seat exposed.
My current buggy has a retro-fitted tube welded in to protect the seats because the first few trips out after building it I managed to tear both seats, one on a rock shelf running parallel to a climb, and one on a tree that we always lean into and pivot around on a nasty off-camber climb.

It looks like shit because it's obviously an afterthought and doesn't meet up with any nodes.

Do you guys with a B-pillar forward of the seats ring your bell on it ever? Talking crawling in a buggy here, I have no experience in bodied rigs or going fast...

 

[desertPOS]

I'll say put the B pillar clear of your head and in a good place where you can actually X the cage, then gusset as necessary - and node tubes correctly. There's a reason that is done in top tier builds, and it wasn't done in that one. But any case I've seen like this is a learning experience - you can look at where/how it failed and take that into account when you're building something in the future... I seriously don't know how he passed tech with that cage though...

 

[gt1guy]

That cage doesn't have a X in the B or C pillar. Zero lateral strength. That cage is scary. It looks like it has some sort of upside down V in the middle of the B, except those bars are almost vertical, he's getting no lateral support from them. Though, they're probably what kept the roof from making him 2' shorter.

The worst part is that there's more than enough room for a second B with a proper X.

Agreed. Zooming in and looking even closer, that B pillar tube doesn’t even go to the floor from the looks of it. It looks like it’s welded to a plate that was attached to the top of the sheet metal square pillar between the doors. Hard to tell for sure in the pics though.

I'm pretty sure his cage B does continue down to the floor. What you're seeing is a gusset they ran from the cage B to the chopped down factory B-pillar. On a 4dr Jk, inside the factory B is a 2" tube that exits the sheetmetal at the top and forms the factory cage. It's only welded to the sheet metal in a couple spots and is what the door hinges/latch bolts to. It's not very strong at all.


You can see in the pic I posted earlier. I dealt with the issue on my 4dr where the factory B isn't in a good spot for a proper X. I drilled out all the spot welds and gutted the factory B, then ran a tube stuffed inside the sheet metal and a second B where I could run an X without any bends in it. The forward B almost touches the outside sheet metal, all the door hinge/latch mounts are welded to it and I trimmed/welded the inner sheet metal back in place. Both B's are tied into the frame.

 

[Socsmm6]

Not mine but I saw this brand new SXS on the trail right after it happened.

Did it take multiple rolls or just flip over backwards?

 

[Wulf]

Did it take multiple rolls or just flip over backwards?

I believe it just flipped backwards but I can't tell you for sure. I was about 200 yard behind them and got there right as they were getting out. When I asked for details they were pretty tight lipped on it and assured me that they were experienced drivers.

They declined our help recovering it and spent 30 minutes dragging it back and forth on its top with the winch on the yellow one before they figured out how to right side it :D

 

[Socsmm6]

I have the 64” version of the xrc. After seeing multiple broke cages im looking for one now. You can replace the upper cage pretty easy but the lower cage/frame is what it is.

 

[SLOWPOKE693]

You can replace the upper cage pretty easy but the lower cage/frame is what it is.

That problem can be solved also. Just depends how far your willing to go.......

 

[SLOWPOKE693]

The entire cage and back of the chassis are all new and made out of much better material.

I stuffed the new cage inside the factory lower B pillar mount and plug welded it in several spots for ultimate strength. I only kept the stock lower B pillar there because the shock crossmember was welded to it, and the rules for the class im racing in state that all suspension mounting points must be stock. If it wasn't for that rule I would have cut it up even more than I did.

 

[JR4X]

That problem can be solved also. Just depends how far your willing to go.......

How long did that take? I’m building an XPT to race and while I would have liked to strip it down and do something like that to it, I just couldn’t devote that amount of time into the little turd.

 

[SLOWPOKE693]

How long did that take? I’m building an XPT to race and while I would have liked to strip it down and do something like that to it, I just couldn’t devote that amount of time into the little turd.

I spent about 2 weeks worth of evenings and weekends building the cage & back half. I have a build thread in the "Other Builds" section here that goes into some detail about what/how I did it.

 

[No way]

I've bent a few A and C pillars over the years but I only had one cage fully trashed.
Dove off a cliff during a national comp, did a couple of corkscrew flips and slammed on my drivers side before we ended up on the wheels. Finished the section though
Scariest part was seeing the kink in the A-pillar where it passed the dash. That pillar must have been bent a lot farther over and then returned to have the kind of fold in it that it had.
This was 2012 so there weren't cameras in every pocket..

 

[YJ-6 Unlimited]

I would say win over fail. Rolled 2-1/2 times hard at Choccolocco after I ran out of
talent on my first trip out after an almost 2 year build. Cage is scratched up and there is a dent in the driver a-b spreader, but I didn’t even have a bruise. IMO the taco gussets really helped.

 

['84 Bronco II]

I would say win over fail. Rolled 2-1/2 times hard at Choccolocco after I ran out of
talent on my first trip out after an almost 2 year build. Cage is scratched up and there is a dent in the driver a-b spreader, but I didn’t even have a bruise. IMO the taco gussets really helped.

Any pictures of the overall cage design? Also, what size and material tubing? Any idea what the rig weighs?

Looks like it held up great, I only ask all these questions to provide more tech for those in the process of designing their own cages.

 

[JR4X]

Forgot I had these, friend of ours from so-cal. Heavy rig due to class rules. High speed roll during qualifying at Ridgecrest a couple years ago. Albert got a bad concussion and his neck seriously hurt because the cage folded in and hit him in the helmet.

 

[Treefrog]

Forgot I had these, friend of ours from so-cal. Heavy rig due to class rules. High speed roll during qualifying at Ridgecrest a couple years ago. Albert got a bad concussion and his neck seriously hurt because the cage folded in and hit him in the helmet.

B-pillar bracing would have done quite a bit to prevent that, correct?

 

[SLOWPOKE693]

Is that a GenRight cage kit in that Jeep?

Doesn't look like 2" tubing, and in my opinion not nearly enough triangulation there for go fast racing. I looked at the Fury Offroad Tires website and it shows pics of that Jeep with the driver in it. Dudes head was at the roof in those pictures before it caved in, Ouch! Im surprised any of that even passed tech... And he is VERY lucky to be alive.

 

[SLOWPOKE693]

B-pillar bracing would have done quite a bit to prevent that, correct?

And not welding plate into the center of tubes..... Not sure if it was supposed to be a gusset or something else but it is a bad bad idea.

 

['84 Bronco II]

Doesn't look like there was an "X" or similar triangulation on the B-pillar hoop, and "family"-style rear portion is much weaker than if he had used diagonal kickers.

 

[JR4X]

Dude built a mud truck with literal aluminized exhaust pipe and it was all kinked up to start with. Nobody got hurt, wasn't even a bad roll, pretty soft landing but exhaust pipe didn't hold the truck up. Major fail IMO.

 

[JR4X]

Is that a GenRight cage kit in that Jeep?

Doesn't look like 2" tubing, and in my opinion not nearly enough triangulation there for go fast racing. I looked at the Fury Offroad Tires website and it shows pics of that Jeep with the driver in it. Dudes head was at the roof in those pictures before it caved in, Ouch! Im surprised any of that even passed tech... And he is VERY lucky to be alive.

Sure looks like a GR kit, but would have had to heavily modify it. The A pillars have to be tube all the way to the floor. I have the GR kit in my trail rig and it has an X in the B pillar, but it's got those stupid press broke plates that go from the dash to the floor instead of tube. Mine wouldn't pass tech for certain but Albert's has more tube than mine.

 

[SLOWPOKE693]

Mud truck has ZERO triangulation. It may have held up slightly better with even a little bit of it.

 

[DMANbluesfreak]

Doesn't look like there was an "X" or similar triangulation on the B-pillar hoop, and "family"-style rear portion is much weaker than if he had used diagonal kickers.

I don't see why they couldn't do both. Keep the X on the roof, add triangulation on the sides from the top of the B-pillar to the bottom of the C-pillar. Then put an X on the back wall between C-pillar to tie in the nodes. It would certainly have helped significantly, even if not the ultimate cage design.