Roll Cage Design

[slcpunk74]

Are you building the cage? If so I would check out dezertrangers. Most rock crawler guys really don't understand the term load path and that makes for a scary cage design when you go fast.

BTW Pm sent.

*EDITED BY ROCKMONKEY* I moved these posts from the Utah Broncospeed thread to keep it on topic. Please continue this discussion here.

 

[slcpunk74]

Good deal. Yeah if you go out to a show like the alljeep show lat weekend you will see exactly what I mean when I say that most wheeling guys have not a clue about cage design. Good luck and we will have to go run sometime.

 

[cruiseroutfit]

Good deal. Yeah if you go out to a show like the alljeep show lat weekend you will see exactly what I mean when I say that most wheeling guys have not a clue about cage design. Good luck and we will have to go run sometime.

I wouldn't say 'most' don't, I would say 'some' don't. Its unfair to apply the logic and engineering behind a high speed vehicle to that of a slow speed recreational rock-crawler. Would it be nice if every off-road rig did have a cage capable of enduring and handling the dynamic loading of a high speed rollover, sure... but its comparing apples and oranges.

 

[neagtea]

I agree with Kurt,
There are some guys that have no clue but most quality fabricators can get the job done. Dustin has had his hands in on quite a few off road vehicles and is very good cou Held work alongside any of the SO-CAL boys.

"S-Can" the center caps.
I looked the rig over, Looking good.
Jeff

 

[slcpunk74]

I wouldn't say 'most' don't, I would say 'some' don't. Its unfair to apply the logic and engineering behind a high speed vehicle to that of a slow speed recreational rock-crawler. Would it be nice if every off-road rig did have a cage capable of enduring and handling the dynamic loading of a high speed rollover, sure... but its comparing apples and oranges.

Apples and oranges..? Well as long as the seed it still a live person and the loads are extremely similar why not build things right? Im going to say most and until I see load path being recongnized in 3/5 wheeling style cages I will never say some.

 

[mbryson]

Apples and oranges..? Well as long as the seed it still a live person and the loads are extremely similar why not build things right? Im going to say most and until I see load path being recongnized in 3/5 wheeling style cages I will never say some.

Admittedly, I don't know what you're talking about. Please start a thread and elaborate? Not that I build any cages.

 

[cruiseroutfit]

Apples and oranges..? Well as long as the seed it still a live person and the loads are extremely similar why not build things right? Im going to say most and until I see load path being recongnized in 3/5 wheeling style cages I will never say some.

Why don't automakers built 'escape pods' for passengers? Incorporate 5 point belts? Why don't we also suggest air bags, ABS brakes and halon extinguisher systems. How about break-away motors? Their are countless safety measures that could be integrated into any and all vehicles including daily drivers.

The reality is, death or injury from recreation vehicle rollovers directly related to faulty cage designs is thankfully extremely rare, thus the cost to engineer, fab and install cages with buzzwords like 'load path', 'nodal alignment' and 'energy channeling'... is outranked. Again it would be nice to see but even things like 5 point belts, helmets, neck supports or even properly stowed cargo would be more efficient at reducing injuries in a recreational 4x4 rig imo.

On that note, I'd love to see some pics of cages you've designed and built, show us how its done.

 

[RockMonkey]

Often it is not practical or necessary to build a perfectly engineered cage around a pre-existing chassis. When I built my buggy it was very well engineered. I spent a lot of time making sure no tube ended in the middle of another tube, that all tubes were supported all the way from top to bottom, and that all structures were triangulated, so the chassis did not rely on the welds to be a rigid structure. When I built the Cherokee cage I made quite a few concessions to the pre-existing structure, to maintain cargo and occupant space, and even to aesthetics (gasp). I could have made a stronger and more "right" cage, but the end product taken as a whole would have been heavier and less usable. Since the vast majority of people survive rollovers in Cherokees without any cage at all, I was willing to make some concessions and have an imperfect cage that was still very strong. I guess my point is that just because what you see isn't done perfectly, don't assume the builder doesn't know what they're doing.

 

[RockMonkey]

I moved these posts out of the Utah Brocospeed thread to end the highjack. Please continue this discussion in this thread.

 

[Mug]

...so the chassis did not rely on the welds to be a rigid structure...

Good call.
And considering most people don't remove/modify major factory built-in structures, like pillars, floors, and frames, we're only making more safe what's already fairly safe in the first place.

 

[UNSTUCK]

Why don't automakers built 'escape pods' for passengers? Incorporate 5 point belts? Why don't we also suggest air bags, ABS brakes and halon extinguisher systems. How about break-away motors? Their are countless safety measures that could be integrated into any and all vehicles including daily drivers.

The reality is, death or injury from recreation vehicle rollovers directly related to faulty cage designs is thankfully extremely rare, thus the cost to engineer, fab and install cages with buzzwords like 'load path', 'nodal alignment' and 'energy channeling'... is outranked. Again it would be nice to see but even things like 5 point belts, helmets, neck supports or even properly stowed cargo would be more efficient at reducing injuries in a recreational 4x4 rig imo.

On that note, I'd love to see some pics of cages you've designed and built, show us how its done.

Well said Kurt. There is a huge difference between rolling, at worst case, down something like Hells Gate VS. rolling over and over in a NASCAR rig at 200 MPH.

I have built very basic cages to cages that were hard to get in and out of for customers. I would feel safer in any of those rigs, rather then by leaving the stock cage in place.




So, can we get some examples of good and bad cages?

 

[Erik d_lux]

FWIW my first roll which was a 2 barrel roll was with my stock cruiser roll bar. This roll bar is the one that has a B pillar and two 90's bolting to the wheel wells.

My floor boards were almost completely rusted out and the cage wasent even tightly bolted to itself. Point is? I was fine. I wouldnt do it again if I had the choice though. A half assed cage will hold up pretty good.

 

[Erik d_lux]

Where my cages fail...

 

[Erik d_lux]

On my next buggy I will try to address the failure in the middle of the dash by tying down to the fram

As for the side bars I added these. I think most people look at them and think its just a bad cage design or me trying to be fancy. Fact is that its real world testing and I have not had a problem since.

 

[Fester]

Does a commuter car or DD truck need to have a "properly designed" cage in it? I don't think so. Applying principles (directly) from another sport isn't always appropriate. I also don't think most off road vehicles need the parachute that dragsters have.

This snowflake roll started at ~70ish mph. 2.5 times over then 3/4 end over end. Driver walked away a little dizzy (and pissed).

 

[I Lean]

It's been a LONG time since I've seen one of those stickers. Good stuff!

 

[Erik d_lux]

It's been a LONG time since I've seen one of those stickers. Good stuff!

Lol. Still rollin it to! Its a bit faded now though.

 

[slcpunk74]

On that note, I'd love to see some pics of cages you've designed and built, show us how its done.

Never even said I was a fabricator did I..? There is a right and a wrong way to do things and just because most wheelers flop and don't cartwheel does not mean they shouldn't build something that can actually save a life if something really bad happens. Dead tubes and lack of load path are no harder to avoid then they are to create...

 

[RockMonkey]

Never even said I was a fabricator did I..? ...Dead tubes and lack of load path are no harder to avoid then they are to create...

So you're an admitted non-fabricator, yet you're making statements on how difficult fabrication is (or is not)?

 

[cuban b]

Less of "look at me I own the fabricator's thesaurus" and more real world cage stuff could turn this into an interesting thread.

Erik D lux posted some of the most interesting cage testing pics I've ever seen. Thanks for those.