TheSamba.com :: View topic - Make my roll bar out of 1.5 or 1 5/8"? updated

Tue Dec 11, 2012 1:38 pm

I was reading the post on buggy roll cages here:
http://www.thesamba.com/vw/forum/viewtopic.php?t=338862

Many are made out of 1.5 OD tube. I am just beginning my fabrication and need some opinions. Are most of them made out of 1.5 OD DOM tube? Suggestions? I picked some up the other day and it seemed a little small but I don't have anything to compare it to.

What do you think? OK, got the pics updated with some larger ones.

Here is a pic of my project with a roll bar that was given to me. This buggy needs everything replaced from wiring to tires and dash board to paint. I probably should redue the tranny as well..... The seat that is in the pic got junked with the bumpers and origional motor.

Tue Dec 11, 2012 2:29 pm

Just use mild steel seam welded unless you are racing, it's less expensive than DOM and will be fine for a street car as far as strength. My cage is 1.5, 090 wall tubing in my buggy. It doesn't pass tech for any sanctioned racing body any more, but my auto-x club turns a blind eye as it's welded to the chassis. If you want to be legal for any type of racing use 1 5/8 .120 wall tubing. Even if you aren't racing that is what I would use if you have the dies for it. 1.75 and 2" tubing is getting pretty big.

brad

Tue Dec 11, 2012 3:05 pm

Having built 4 buggy cages this year, ^^^^^ that is some very good advice. I only use 1 5/8 0.120 wall tubing. My preference is DOM, but welded seam is perfectly fine.

Tue Dec 11, 2012 6:34 pm

NHRA and NASCAR requires 1 5/8" x .120". On a lightweight steet Dunebuugy your probably OK with 1 1/2" x .120. For a sand only buggy everybody uses 1 1/2" x .095"

Tue Dec 11, 2012 7:22 pm

slalombuggy wrote: Just use mild steel seam welded unless you are racing, it's less expensive than DOM and will be fine for a street car as far as strength. My cage is 1.5, 090 wall tubing in my buggy. It doesn't pass tech for any sanctioned racing body any more, but my auto-x club turns a blind eye as it's welded to the chassis. If you want to be legal for any type of racing use 1 5/8 .120 wall tubing. Even if you aren't racing that is what I would use if you have the dies for it. 1.75 and 2" tubing is getting pretty big.

brad

Pretty much agree with above...

My cage on my street buggy and on race car which I just sold is 1.5 X .120 DOM but if I were to do it again, I would go with 1 5/8 X .120 DOM so IF car is going to be raced it will pass tech.... It may also save my head in a incident..

Include doing 6 inch square floor plates so it does not punch through pan and all the technical stuff, to be track legal....

1.750 or 2 inch is to big, costs to much in weight and adds little additional protection....

Dale

Tue Dec 11, 2012 9:38 pm

Dale, Does the 6 inch square floor plate still apply if the tub to pan bolts are used in the rear corners?

I'm trying to get as much room behind the seats as possible.

Larry

Tue Dec 11, 2012 10:36 pm

Yes it does, but, the bar doesn't have to be centered on the plate and it can be any 4 sided shape, as long as there are 24 inches around the perimeter of the plate, ie 7x5 or 8x4. My last floor pan chassis had the main hoop welded 1" in from the rear edge of the plate and about 1.5" in from the sides to get some seat room. You also need a minimum of 2" of room between your helmet and any top bars your helmet may come inot contact with.

brad

Tue Dec 11, 2012 10:50 pm

I'm going to try to use a Greenlee 1818 bender for my project - This will be my first cage. I will swap out my 1.5 tube and use 1 5/8" as I may want to try Auto cross in this.

Thanks for all the help. I'll post some pics as I start bending.

Tue Dec 11, 2012 11:11 pm

Here is another few ideas I have done to mount the cage to the buggy. Underneath is a like plate to sandwich the pan and body.

For my light blue buggy

For Keith's dark blue buggy

Davids Buggy. Used a 1 X 2 body lift that the cage bolted into.

My silver buggy

My Yellow Buggy

All used 3/16 steel as the weld to plate and then bolted through the body and pan with plates underneath to form the sandwich. Rear bars all tied into the rear suspension to form a true 6 point cage.

Wed Dec 12, 2012 8:12 am

Driftin wrote: I'm going to try to use a Greenlee 1818 bender for my project - This will be my first cage. I will swap out my 1.5 tube and use 1 5/8" as I may want to try Auto cross in this.

Thanks for all the help. I'll post some pics as I start bending.

It will probably work if die is for tubing and it is proper size.... Remember "pipe" dies are for larger outside diameter of pipe but designated by ID of pipe, tube dies are designated by OD of tube .... IF die fits tube properly it will be ok... If tube is loose in die it will squish at bends or kink.... Also radius of die will make difference in appearance... Rule of thumb (sort of) is minimum radius of bend is about 3x diameter of tube..... 5 to 6 inch radius look pretty good larger radius look awkward and start taking up a lot of "space"...

In my race when it was build... We used a large "L" shaped piece of metal at outer rear corner of tub and gusseted with another piece that was laid on inside corners vertically and used 4 bolts through pan and a matching plate under corner piece... Not exactly by rule book, but it provided maximum attachment to pan...

Little primer to help you out...

http://www.pirate4x4.com/tech/bendin_tube/index.html

Dale

Wed Dec 12, 2012 5:11 pm

The radius on my bender for 1 1/4" EMT = 1 1/2" Tube is 7 1/2". Sounds like it is to big. I'll have to look for another tool for this. I need a bigger shop....

Wed Dec 12, 2012 6:51 pm

I doubt that you would be successful in bending roll cage tubing with an EMT bender anyway. EMT is much thinner and easier to bend than the DOM or CREW tubing you would be using to build a rollcage.