Roll Bar Input

I'm having a roll bar made for my '58 CJ5. I will have a back seat so I'm having it made with loops that go high enough to protect the occupants. I'm not going rock drawing or any extreme stuff. Just basically forest roads, trails, and some help if in a car accident, rollover. Basically like this, possibly minus the front to the windshield:



I have 2 questions I'm looking for input on. First, should I consider a bar across the top of the rear loops. I'm afraid it would pose a head hitting risk, yet without it, it seems like it would be easier for the rear loop to collapse inward. Second, I'm sure the windshield would collapse with little effort. The cages I've seen where it comes forward and then down the front of the dash where your legs are. But these make it difficult for a tall, large person to get in and out. The builder suggested coming down and attaching just below the window frame where the dash bolts to the sides. Input? And cross brace to keep these from bending in? I'm not really interested in a 'full' cage as it just feels too 'cagey' if you know what I mean. Especially given the relative mundane driving we will be doing.

 

A Jeep is not really safe without a roll bar of some type.
That's my opinion.
To each his own.

The red CJ5 rolled pulling a house trailer down the freeway.

The blue CJ5 was rolled by a high school lad who came home at lunch and drove the Jeep
without Dad's knowledge or permission.

If you look closely, you can see the front cage in both Jeeps.
Yes, the windshield frames are bent and destroyed, better them than you.

 

digging the 68 pontiac in that first one...

 

I agree a roll bar adds some safety . but a cage is much safer . if it does flip

 

It is important to insure that the rollbar is attached to the frame, not just to a rusty rotted section of the rear fenders.

I rolled a 59 jeep sideways in my small backyard back in 1969. I was young and stupid, had my nephew in the passenger seat, and my two nieces all under age 7 in the bed. windshield down. Slipped sideways and hit a hole on a right turn, and flipped upside down. Nieces in back saved by the spare tire mounted on the back. Nephew not so lucky, got pinned under windshield and broke his leg. I was able to bail out on the way over. These old jeeps have narrow wheelbase and rollover at low speed under certain conditions.

30 years later my son was a rear seat passenger in a jeep rollover. Jeep was equipped with roll bar cage and 3 point harnesses. on a jeep trail, the jeep hit some soft area and rolled sideways and slid down a hill. Drive and my son were fine, the passenger in the front seat had hit his head on the rolll bar when it landed, he was dead at the scene. He had been sitting on the 3 point harness.

In both cases, there was very little damage to the jeeps.

 

Not digging the front hoop attached to the dash. A good fabricator can make the extra bends to keep the tubing tucked up next to the dash and tight to the body. If you have a good steel body a suitable floor plate with a larger plate under the floor is generally suitable for low speed events. Jmo its not that big a deal to fab a frame tie in at that point. The rear hoops need at a minimum a bar tieing them together.

 

As far as the front hoop, getting in and out is a momentary inconvenience. Weigh this against safety and peace of mind.

You can likely get the rear bar high enough.

 

Same here but also with at least 3 point belting. I won't get in a Jeep without both.

And the fenderwell mounted roll bars do work IF you have a solid tub and a backing plate below. I dynamically tested one at 50 mph. Sank the tub rails down about 2" at the front of the bar but nothing tore loose. And yes, I did get the windshield in my face but otherwise pretty much uninjured. And the roll bar wasn't even bent-reused it.

As for the cage, I would also want the A hoop. If you go with 1.5" DOM, you should be able to put the extra bends at the bottom to tuck it in tight to the tub with minimal intrusion on available space. Again, if the tub is solid, a backing plate will suffice for mounting. To actually frame mount the A hoop requires some engineering to be done correctly. Otherwise, it's just good for the warm fuzzy feeling.

 

Here is a shot of the front section of my cage and how it bends out of the way of your legs. I made the cage bolt to the floor and to the dash, adding lots of rigidity to the tub and spreading out load. There is a double spreader bar from front to rear. Entire cage is 1.5" DOM tubing for easily wrapping your hand around.

 

That pretty much describes the condition of my CJ when I got it....the PO had a similar experience on an icy bridge in Montana.

 

my cage bends in like this not a problem on access. i think ill add the dash tabs too

 

I really like how much more positive the whole jeep feels with the dash tie in. I made them out of some 1 1/2" angle iron, My bars are close to the dash other people may need to use larger angle if theirs is farther away.

 

If someone has a schematic of how these cages tie into the frame and they are close up to the dash so as to not be in the way, I would be interested in seeing some do's and don'ts.

 

My wiper are top mount so can't run along the top of windshield like this.

 

Mine are top-mounted. Front roll-bar runs directly over them.

 

I have a buddy who said he has an extra Hossfield bender i can borrow from him.....

I went to a place that has real rocky trails and my sons were telling me I should go drive my jeep there. Before I do any of that I will build a cage. 1.5 or 1.75 DOM tube with what thickness wall?

 

.120 Dom is generally considered adequate for our low speed purposes.2" main bar and front hoops can be reduced to 1.5 od if you want to make bends tuck in tight to windshield and body.

 

Well one thing for sure , I'm glad to finally see a civil conversation over roll bars , cages & safety.......to often this conversation turns controversial between the I want to keep it stock looking and roll bars are only for race cars to anything in between, while some live by the single loop behind and over your head while others look for a more complete cage with a front hoop and down tubes while others say it's a waste of time if it's not connected to the chassis..............One thing for sure is no one knows how much protection they will need to walk away until after the next event occurs.

Trail riding , rock crawling, in the sand , A slow roll on it's side, multiple rolls down a hill , or just getting smacked in an intersection! The old adage that you can be just as dead at 5 mph as you can at 100 mph still holds true in all incidences.

Personally I think DOM tubing should be considered as the minimum tubing of choice.....although I still use 4130 as it allows for a smaller tube diameter ( 1.625") and lighter weight ( .083 " wall ) to be used in tight places without loss of strength.........1.750 x .120 DOM should be adequate if proper bracing and diagonal's are applied in the correct locations............2" OD is a little large for tight spaces in an already tight Jeep environment.......and by all means if you can connect it to the chassis vs the 18 gauge sheet metal body components then do it...........and don't forget your restraint systems......single 2 or 3 point basic seat built systems will hardly keep you in the cocoon in the event you roll over............I still like the advantage of having a 5 point system on board whereby if you see the going is getting tough then buckle up and cinch them down.

 

I guess I know what my next project is going to be.

 

My cage is 1.5" .095 dom. You can see in the pics that all joints are gusseted including the two overhead spreader bars. My cage was built to barley fit inside a soft top.
I would find a way to fit a front hoop in there with the top mount wipers.