HMMVW roll bars

[98G]

That's what I was thinking also , there is nothing going to the frame.

I speculate that it depends on the speed at which it happens. A motor vehicle collision with rollover at highway speed probably won't end well.

On the other hand, offroad rock crawling and havr a lowspeed roll over those roll bars may be the difference between walking away unscathed and DRT...

 

[ZZZZZZCOBRA1]

Looks good. What size is the main loop behind the C pillar?

 

[Milcommoguy]

Look like nice work and quick too. Got to be better than just the "C" pillar. Tie it in to the the other pillars for the compete deal. Check out "Bulldogger's soft slant top set up. Might team up for something new to the cause.

Make $$$$ too........

Just saying, CAM

 

[Dock Rocker]

That’s an ornament not roll protection.


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[porkysplace]

I speculate that it depends on the speed at which it happens. A motor vehicle collision with rollover at highway speed probably won't end well.

On the other hand, offroad rock crawling and havr a lowspeed roll over those roll bars may be the difference between walking away unscathed and DRT...

I've test a couple of stock factory roll bars in CJ's one at highway speed and one in a gravel pit , and without being tied to the frame it is just giving you a false feeling of security.

 

[lowell66dart]

The main hoop is 2 3/8's. The other tubes are a little under 2 inches. Easier to weld. This is much better than counting on the C pillar for anything. Hopefully I don't ever test it but it is much better than nothing,

 

[98G]

I've test a couple of stock factory roll bars in CJ's one at highway speed and one in a gravel pit , and without being tied to the frame it is just giving you a false feeling of security.

I would be interested in data from a walking speed rollover with a rollbar which was not tied to the frame. Even a sample size of one would be interesting.

I saw a video of a stock jeep that got sideways on a hill and rolled sideways for maybe 20 revolutions. Looked like the occupants were unscathed.

We have the recent footage from Oregon of the hmmwv that was struck and rolled and the occupants were (more or less) ok. I didn't see any rollbar in evidence.

All that being said, I'm kind of of the opinion that if you're going to go to the trouble to fab a rollbar, you may as well take it to the conclusion and tie it to the frame....

 

[Milcommoguy]

It's a hobby, coupled with your design for a limited / additional protection I think your on target. Surplus hobby HMMWV's is the canvas to do your thing. Now, if YA had lots of sponsors, BIG daddy bucks to burn, design, cut and weld all night from the frame up.

Definitely adds a level of protection (weld are good right) for where I see these rigs parked at the IHOP or cruising the mall. Want to see some messed up HMMWV's fails, search the UTUBE.

Looking back on the whole HMMWV thing... how far do you go before you end up full armored, can't roll down the road and broke.

And I get all the heavy duty stuff. Now, where's the "D" ring for the ejector seat.

CAM

 

[lowell66dart]

The welds are all tigged. I now have a graceful way to get in the back of this thing. Grab the bars, put a foot on the tire and I'm in.

 

[Bulldogger]

Look like nice work and quick too. Got to be better than just the "C" pillar. Tie it in to the the other pillars for the compete deal. Check out "Bulldogger's soft slant top set up. Might team up for something new to the cause.

Make $$$$ too........

Just saying, CAM

My current design wouldn't fit as-is, due to the gap between the ear leg and the rear corner. Not sure I could make a cover to fit well, bc of that gap. A piece of EMT conduit placed on the inner or outer side of each ear leg down to the back corner might make it workable. Not a lot of center support though. Probably flap in the wind a fair bit. Still, it's do-able with a couple more lightweight supports.

BDGR

 

[08hmmwv]

Does anyone know what brand or where I can find these roll bars.

 

[911joeblow]

So frame mounting is the way to go BUT if you spread the load over a large enough surface area then these types of bars can provide good rollover protection. In unibody racecars (my background) we had no frame to weld too, so the floor and the wheel wells and the rockers were used all the time. I have personally been in a nasty crash at 180 MPH and went over several times ending on the roof with one such cage and walked (OK limped) away in pretty good shape. So if you look at the SF cages, they are using the entire length of the upper fender for support so from a surface area perspective, there is a lot! The fenders themselves will fail in a big crash but they are absorbing load while they are deforming so they are working but eventually there will be structural failure to the point where the occupants will have diminished head room. Braces running from underneath the fender diagonally inward from the feet of the cage to the frame rails could be placed on either side of the wheel which would tie up the cage nicely. The front windsheild area is a bit trickier but I have found that by doing a 'halo' around the windshield with a center post, then two posts under the hood to the frame rails will do a good job there. Lastly the center area near the 'B' pillar can use the frame braces to help distribute the load.

 

[sue]

So frame mounting is the way to go BUT if you spread the load over a large enough surface area then these types of bars can provide good rollover protection. In unibody racecars (my background) we had no frame to weld too, so the floor and the wheel wells and the rockers were used all the time. I have personally been in a nasty crash at 180 MPH and went over several times ending on the roof with one such cage and walked (OK limped) away in pretty good shape. So if you look at the SF cages, they are using the entire length of the upper fender for support so from a surface area perspective, there is a lot! The fenders themselves will fail in a big crash but they are absorbing load while they are deforming so they are working but eventually there will be structural failure to the point where the occupants will have diminished head room. Braces running from underneath the fender diagonally inward from the feet of the cage to the frame rails could be placed on either side of the wheel which would tie up the cage nicely. The front windsheild area is a bit trickier but I have found that by doing a 'halo' around the windshield with a center post, then two posts under the hood to the frame rails will do a good job there. Lastly the center area near the 'B' pillar can use the frame braces to help distribute the load.

 

[sue]

We used 2X3” 1/4”wall tubing for “B” pillar 1X3” 1/8” wall for “c” pillar, 2X2” 1/4” wall for the A pillar.
With 1X1/5” 1/8” wall for the diagonal (speed braces) Fits under the hard top. And all the pillars and associated cage supports are bolted together up vertically. Love it.

 

[knighthawkgamer]

We used 2X3” 1/4”wall tubing for “B” pillar 1X3” 1/8” wall for “c” pillar, 2X2” 1/4” wall for the A pillar.
With 1X1/5” 1/8” wall for the diagonal (speed braces) Fits under the hard top. And all the pillars and associated cage supports are bolted together up vertically. Love it.

Would love to see some pictures of your setup.

 

[rcamacho]

Agreed, love to see pictures of a functional structural cage that works for a 4-man


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[sue]

Agreed, love to see pictures of a functional structural cage that works for a 4-man


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Ok, it’s about time we come in to the 20th century
We have iPhones, tell us in simple terms how to put pictures on here?

 

[sue]

Ok, it’s about time we come in to the 20th century
We have iPhones, tell us in simple terms how to put pictures on here?

 

[sue]

View attachment 791923

Here’s the first picture we ever posted!!
We made the hard top, but it would work with a soft top also

 

[sue]

Here’s the first picture we ever posted!!
We made the hard top, but it would work with a soft top also

Here’s how the “A” pillar came out with the wiper motor