Roll cage design lessons learned?

[TonyPDX]

Hey folks, we are in the process of designing a roll cage. I am looking for feedback on what you have learned from cages you bought or built. What do you wish was different?

My priorities are:
1. Increase safety in an accident (on and off road)
2. Provide shoulder belt mounting points for front and rear seating positions

In reference to priority #1, motor vehicle accidents: “In the western world, the most common cause of death after trauma is severe brain injury. The incidence of death from head injury is approximately 7 per 100,000 [14], and the severely brain-injured also have the highest mean length of stay and mean hospital costs…” therefore we are placing the tubes as far away from the passenger’s heads as possible and they will be padded with proper SFI padding.

Thanks, Tony

 

[Rustytruck]

Make sure you put in appropriate hand holds before you paint it. I welded tabs on my roll cage to go to the front windshield mounting bolts.

Make sure your floor mounting plates are actually mounted to solid metal and make sure the support bar behind your head cant just push through the floor. Make support so it contacts the frame. The body is only mounted to the frame by a few bolts so make sure these are good and solid. Allot of these Broncos are very old and rusty and most of the bad rust is in structural areas.

 

[FordBronc]

A roll cage bolted to thin floor panel sheet metal is as good as the sheet metal is real thick and capably of supporting a load....not really IMO.

Think frame tie-in into your design. You can still bolt (grade 8 or better bolts) it to the floor pan, think support from underneath the floor pan to the frame.

Think rock slider/hard mount nerf bar idea that protects your rockers/giver you a step and ties the cage to the frame all in one.

 

[toddz69]

therefore we are placing the tubes as far away from the passenger’s heads as possible and they will be padded with proper SFI padding.

Tubes away from the head is always a good idea! Regarding the SFI padding - most of the different grades of the SFI stuff is still super hard and good for hitting with a helmet - not your unprotected melon.

I found and use this material on my cage. Not cheap but I think my noggin will thank me with a hard hit:

https://www.pegasusautoracing.com/productselection.asp?Product=2397

Todd Z.

 

[Capt.junk&crap]

FordBronc, I want to do the Nerf/slider bar/cage tie in like on the orange Bronco in your pictures. Do you have any more of those pics?

 

[Skiddy]

Think rock slider/hard mount nerf bar idea that protects your rockers/giver you a step and ties the cage to the frame all in one.

not sure about having to tie to the cage, but it will sure protect on a side impact, which is one we don't really consider much.

 

[ObscureMachine]

I read on here once that if the seatbelts alone are tied into the frame, and the body itself breaks loose from the frame, you're SOL. I've heard tie the everything (seats and belts) into the roll cage so it will all break loose together, if it does. I can envision belts being tied into the cage but also the floor being problematic in a rollover if anything breaks loose, as in being the passengers being torn apart.

 

[TonyPDX]

Tubes away from the head is always a good idea! Regarding the SFI padding - most of the different grades of the SFI stuff is still super hard and good for hitting with a helmet - not your unprotected melon.

I found and use this material on my cage. Not cheap but I think my noggin will thank me with a hard hit:

https://www.pegasusautoracing.com/productselection.asp?Product=2397

Todd Z.

Thanks, Todd that is a really good idea. I do want it hard enough to protect my head in a real accident with no helmet. Based on some research I have been doing the pipe insulation type of padding will do almost nothing in an accident but likely helps a lot if you bump your head getting in/out of the vehicle.

 

[68ford]

https://waynesbronco.shutterfly.com/468

What under my half cab. Welded to the frame at all point except by my feet. There where I did the normal sandwich plate with 4 bolts, I put a 3 in long piece of 1.5 dia tube going through like a pilot. This makes it like 1 complete tube in theory and not placing the load on the 4 bolts. Obviously excessive for most but maybe you will get some ideas.

Build a cage to go behind the dash making the dash bolt to it instead of the cab. Tubes much closer to the A Pilar and look way better than the normal S bend around the dash. Plush no glove box or window crank issues

 

[toddz69]

Based on some research I have been doing the pipe insulation type of padding will do almost nothing in an accident but likely helps a lot if you bump your head getting in/out of the vehicle.

That is my understanding as well. BTW - there are other sources for that padding out there besides Pegasus. They're handy, but not always the cheapest.

Todd Z.

 

[Digger556]

Tubes away from the head is always a good idea! Regarding the SFI padding - most of the different grades of the SFI stuff is still super hard and good for hitting with a helmet - not your unprotected melon.

I found and use this material on my cage. Not cheap but I think my noggin will thank me with a hard hit:

https://www.pegasusautoracing.com/productselection.asp?Product=2397

Todd Z.

I bought a ton of that padding on Todd's recommendation. Good Stuff! Highly recommended!

 

[nvrstuk]

Tony...I agree with the head injury precautions... Hand holds, CB radios all that crap that that's bolted on...anyway, local guy died years back (officially) from trauma to his head on his CB that was mounted on his cage...

I see these tubing style "oh sh*t" handles that stick out 6" or more from the cage to help people hang on or climb in and they look like they are begging for a forehead to split open...

I lowered my floors last year for two reasons:

1) safety- my head isn't even close to the tubing

2) visibility out the windshield

3) easier to climb in for my wife


Ironic that we build cages to protect us and then in some cases they do the opposite...

Message me when you come up with a design OK?

 

[grant_71]

A roll cage bolted to thin floor panel sheet metal is as good as the the sheet metal is real thick and capably of supporting a load....not really IMO.

Think frame tie-in into your design. You can still bolt (grade 8 or better bolts) it to the floor pan, think support from underneath the floor pan to the frame.

Think rock slider/hard mount nerf bar idea that protects your rockers/giver you a step and ties the cage to the frame all in one.

Where did you get that second pic? Is that an Inventor assembly??

 

[ntsqd]

One friend is building (& on and off has been for the last 15 years.... ) a 5.0 powered flat fender. He has added structure to the whole tub that the cage bolts to, the main hoop sits on a "cross-member" welded into the tub that closes the upside down 'U' of the main hoop. The kick panels have structure in them that allow the windshield hoop to bolt to the dash at it's outer-most edges. All of his 14 new body mounts are tied directly to this added tub structure.

When the Bronc-up was built structure to tie the bottom side backing plates back to the frame was included. These consist of short tubes with Hega joints at each end. One end bolted to tabs on the frame, the other bolted to tabs on the bottom doubler plate. I don't have a good pic of them, but one can be taken if needed.
It's dash was narrowed so that the windshield hoop legs could be straight and not create entry/exit problems. Those 'S' curves around the dash are big, red neon arrows saying "Collapse here in the event of an accident!".

Only thing that I can add is, sleave all holes in the tubing and do not weld hardware to the cage.

 

[Broncobowsher]

Don't add so much that you make it top heavy.
Asymmetrical front down bars. Sit in the driver's seat as you place them. You can align them with the A-pillar. Done this way there is minimal impact to visibility. It means the left and right bars are in slightly different locations.

Head injury. I got a concussion a couple years ago in a new Ram truck. I was a passenger on a really mild trail. Low speed stuff. Left front dropped into a hole and the body rotated. B-pillar clobbered me. Knocked me stupid for a few minutes and was in a haze for a few days. Maybe we need to start putting containment seats and helmets as standard trail gear?

 

[ntsqd]

....... Maybe we need to start putting containment seats and helmets as standard trail gear?

Pretty much std practice with ATV's and UTV's. I bet even a bicycle helmet would help a lot, and be a lot lighter and less hot.

 

[Digger556]

Don't add so much that you make it top heavy.
Asymmetrical front down bars. Sit in the driver's seat as you place them. You can align them with the A-pillar. Done this way there is minimal impact to visibility. It means the left and right bars are in slightly different locations.

Head injury. I got a concussion a couple years ago in a new Ram truck. I was a passenger on a really mild trail. Low speed stuff. Left front dropped into a hole and the body rotated. B-pillar clobbered me. Knocked me stupid for a few minutes and was in a haze for a few days. Maybe we need to start putting containment seats and helmets as standard trail gear?

That was a big reason I spent $$$ on the better SFI dual durometer padding. ( I head butted it with gusto a few times for testing.)

 

[omureebe]

Would love to see some pictures how rear three point seatbelts are mounted. Seems with the rear seat being between the wheel wells where you attach the mounting point on the cage would be awkward.

 

[SteveL]

One thing to watch for if your looking for head clearance is don't go too wide. When I built the 1st cage on the 72 I went as high and wide as possible. The cage isn't leaning against it but running topless the door frame rattles on the cage on bumpy roads. One of these days I'm gonna put a piece of rubber up there.

 

[jim3326]

I didn't go so far as to tie the cage to the frame but I did reinforce the front and middle cross supports and tie them to the rocker. The rear has a sandwich plate welded to the support. Seats and harness attach to the cage and it all bolts to the plates under the body. Main hoop also bolts to the B-pillar.