Roll Bars

I have a CJ6 that I'm building. Eventually I have to think about the roll bar. What are the suggested methods to build and mount roll bars? Which are the worst mountings for a roll bar?

 

“Suggested” is 1 1/2” minimum outer diameter, .120” wall DOM tubing. If doing it yourself, a dedicated tubing bender will be necessary (not a pipe bender). Ideally, every point that mounts to the body should continue through to the frame.

There are companies out there who sell just the parts for you to weld in, if that’s a route you want to go. Google Images is your friend for mounting ideas.
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http://boyink.com/cj6/rollcage/

I tried looking here but the site shows "ERROR"

 

Worst mounting? Maybe the factory bars that sat on the rear fender housings?

But at the time it was an improvement over 'nothing.'

 

My CJ was rolled, at hiway speed, with one of those. The driver survived with minor injuries.

 

Raced for SCORE years ago, here are their rules. I am using 1.750” x .120” DOM with the windshield, middle and rear hoops all going to frame.
My wife, kids, and grandkids one day may benefit. Octatiel Wells, Glamis dunes, Devils Playground dunes are all within 2-3 hours.

Courtesy of SCORE
1.500” x 0.095” CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
2001 - 2500 lbs.
1.500” x 0.120” CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
2501 - 3000 lbs.
1.750” x 0.095” CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
3001 - 4000 lbs.
1.750” x .120” CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
Over 4000 lbs.
2.000” x 0.120” CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM


Construction Procedures
Cages must be securely mounted to the frame or body and gusseted and braced at all points of intersection. Cab or body mounted cages must not be attached to the body structure by direct welding, but must be bolted through and attached by the use of double plates (one on either side) with a minimum thickness of .187”, see Figure 4. Where bolt and nuts are used the bolts shall be at least .375” diameter SAE Grade 8 or equivalent. Roll cage terminal ends must be located to a frame or body structure that will support maximum impact and not shear.
Minimum material dimension requirements for roll cages apply to the following members of the roll cage:
(1) Front and rear hoop
(2) Front and rear interconnecting bars
(3) Rear down braces
(4) Lateralbracing
(5) Elbowanddoorbars
(6) Lower A-pillar tubes, and lower B-pillar tubes
Roll Cage Design
All roll cages must be constructed with at least one (1) front hoop (top of cage to floor), one (1) rear hoop (top of cage to floor), or two (2) lateral hoops, two (2) interconnecting top bars, two (2) rear down braces and one (1) diagonal brace and necessary gussets, see Figure 1. If front and/or rear hoop terminate at elbow/door bar, lower A-pillar and/or B-pillar must be made of same tubing size as roll cage. Upper main, front, rear, and lateral roll bar hoops must be made in one piece without joints. Centerlines of all required tubes must converge at intersections.

Dennis

 

I’d imagine that when it comes to roll bars in a wheeling Jeep, anything is better than nothing...well almost. I always liked the “family cages” on the cj6s.

 

I personally tested one of those at 55 mph in 1972-a complete somersault. The roll bar sank the wheel houses down about 2" but absolutely nothing came loose. If you have solid sheet metal and a backup plate on the bottom, they actually work as intended. That roll bar didn't have any deflection that I could measure after that incident and is still in use today. There is little doubt a frame mounted one is a better solution (if properly engineered) but it's not the only solution. As always, it comes back to the intended vehicle use.

 

Thanks to everybody for all the advice and suggestions.

 

I ordered this front hoop add on today.
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Going Colorado wheeling this summer this makes me feel a little safer. The price is pretty good and I have a good 220 Mig welder.

Got to decide if the spreader bars go inside or out???

 

Out is stronger but your head will want em inside after the first time you mash it getting in.

 

Spreaders on the inside and big gussets are my choice..... unless you intend to roll..... we will hopefully have pics of Steve's new cage soon.

 

Roll bars and chosen levels of protection are a timeless discussion.
One thing I don't see a lot of discussion on is restraint. I've been suprised multiple times by how well even factory bars have held up yet the belt mounting points tore out or the factory shoulder belt did not keep the occupant in.
Granted 4-5pt is a pain under some circumstances and questionable for DOT use in many states. If you up the ante cage wise but end up flailing around in the sphere of death you may as well have gone au naturel and jumped imo.

 

This is the route I went, the pre-bent , build it yourself cage from Extreme Custom Mfg. as stated above. I now have it tied into the rock sliders which are tied into the frame. I haven’t tied the rear into the frame yet and not sure if I will. With the seats mounted to the cage and four point harness, even in the unlikely event that the cage is disconnected from the body I’d still be in the cage. As far as the upper supports, I’ve hit my head once driving a back road with just the lap belt on and It wasn’t fun. Just gotta keep myself strapped in. I live in California and haven’t been pulled over yet for the harness, my argument will be that it came with lap belts so I’m much safer this way! Even my brother who is a Deputy Sheriff said I probably wouldn’t have a problem.

 

My issue with 4 or 5 point harnesses is that they're a pain to put on, so a lot of people wind up not putting them on...especially for a quick run to the store or something and thats when some fool runs a stop sign and crashes into you.
If you can honestly say "I'll wear them EVERY time I drive, them they're great.

 

Not the best photos, but this is what was in my 6.

 

Was?