I have done searches on roll cages and I have not found what I was looking for.

My question is for the tube that would be by the windshield, what is the strongest? :

a) One main tube that would go from the driver floor by the feet up and around the wind shield to the passenger floor. Then have tubes going to the main hoop by my head behind the seats.

b) Or a tube on both sides that starts from the floor by the feet up to the windshield and bends back to the main hoop by my head. And then have a bar from the driver side to the passenger side near the windshield.

c) Or tube that goes from the main hoop by the drivers head, bend at the windshield then go towards the passenger wind shield then bends back to the main hoop by the passengers head. Then by the windshield on both sides have tubes going to the floor.
:confused:
By the way this cage will be tied into the frame, right after the tube is bent and welded together.

When I built my cage, I went with option b (bar from floor to rear cage, then bar between the two sides)...

I did this cuz I figured that it would be stronger to have 2 full bars, plus the 2 spreaders rather than 4 bars like the spreaders if that makes any sense.

However, I think either way is within 5% of the strength of the other, just gotta make sure you have good welds and tubing...

Originally posted by thejunker
, just gotta make sure you have good welds and tubing...

I think this is the key just as long as the cage is designed correctly. If the welds are good, they should hold.

My cage builder suggested b) as well. Good to know.

For tubing is ERW 1 3/4" .120 wall okay?

Thanks,

Originally posted by sfraser
My cage builder suggested b) as well. Good to know.

For tubing is ERW 1 3/4" .120 wall okay?

Thanks,


Yep.

I went with option a on my cage. My thoughts were that I would rather have more hoops around me than tubes with right angle bends. Not that there is anything wrong with the type b design. The idea of independant hoops just seemed safer to me though I have absolutely no data to back that up.

D.O.M. or chromoly would be way strong, its exspensive but will get the job done.:skull:

Just avoid making excessive bends and triangulate it to create a rigid structure. You may also want to put an x of some sort by the driver and passenger to act as a side impact beam. Try to place the tubing as far away from the occupments as possible so that it has room to crumple if it needs to. Look at NACAR design and any other types of expencive racing vehicles. Even monster trucks show alot of tubing to get ideas off of. Most of these manufacturers already put excessive time and research into the design.

I went with option A as well. This is my logic. When I roll it to the side I want a solid structure there, the hoop. When I roll it over on its nose, I have the triangulated support going from the front hoop to the middle (which is braced to the rear). When I flop it on its back I have the spare to keep from impacting directly on the rear hoop even though its triangulated to the main hoop its not brace to the front (3 hoops, front,middle,and rear) giving the force a chance to disipate before it rolls up on the main hoop.

Here are some early pics of my cage. I am putting a brace across the main hoop to mount my harnesses and to triangulate the main hoop vertically, another braces under my seats. And 6 tie-ins to the frame.

Magoos Heep (http://community.webshots.com/user/wheelinmagoo)

Thanks guys that helps me out alot. I have lots to think about now.