[ Closed ] Roll cage options.. (Page 2 of 3)

The short answer is, yes, you can use chromoly.  But it still has to meet the minimum size and thickness requirements outlined in the rules.  They don't specify material, other than, "Properly bent, racecar-grade and -quality tubing is mandatory."

I imagine some of the frustration in the replies to this thread come from the fact that you seem to not have read the rules about cages, or you seem to think that they don't apply to you if you have a "better" way to do it.  Trust me, Jay and Co. don't give a crap whether your way is better or not; if you get hurt and the cage doesn't conform to the rules, the insurance company won't cover it and the organizers would be liable.

The straight and simple way... read the rules, and follow them to the letter.  Look at the thread referenced above for examples.

This is all really moot anyway, if you don't build a cage that meets the rules, you're not racing, period.

Dave as you know the problem is Chrome moly is slightly differant than DOM in size..   Much, much, stronger but slightly smaller. 
that's why I asked about wiggle room.. Racecar grade does include Chrome Moly since so many race cars use Chrome Moly.. 
  Chrome Moly dies for bending are slightly differant than DOM and you need a whole lot more pressure to bend it.. a lot more!

You're fighting two problems: insurance underwriters and rule simplicity. If Jay wrote the rules so you could make a NASA-style cage, and allow a NASCAR-style cage, and allow an NHRA-style cage, somebody would screw up and mix cage styles. The tech inspector might not catch the difference in styles. Then they'd get in a wreck. The family would sue because the rules were too confusing. Jay's insurance company would refuse to cover it because the cage didn't meet the rules EXACTLY AS STATED. Lemons, as we know it, would end.

You might be able to get Jay to approve your NHRA-cage plan, but don't count on it. You would have to bring your special approval paperwork with you to every race, and even then the tech inspector would sweat you pretty hard. He might even get a hair up his butt to disallow your cage, and if Jay isn't handy to tell him otherwise (he doesn't make it to all the races) you're up $#!+ creek. It's a whole lot easier to just build the cage to meet the rules AS STATED.

Again, read the rules.

If you built a narrow cage and tried to "extend it" to meet the rules, it wouldn't be approved because the rules specifically say that "Each major load-bearing member must be formed from its own single, continuous tube."

Extensions aren't required.  A cage that is properly built to the specifications stated in the rules is required.

I'd bet that you could probably get a waiver to use your smaller diameter Moly tubing, but you'd still be expected to meet the rest of the cage criteria.

dude... DOM really isn't expensive enough to warrant all this arguing to try and get past it. hundreds, maybe even over a thousand teams now (definitely cars) have plopped down the $5-600 for the materials. You could probably get an OK bender for $300(or borrow someone else's) and you already have your own welding equipment, im sure. that's maybe $1000 which is cheap compared to some of us forking out to have a shop do it. If you honestly want to discuss this further, Hit up John or Jay; Their Opinion of what you're trying to do will make or break whether you'll be allowed to do it. Hell, write back here when you get your answer so we know in-fact whether it's acceptable. Otherwise...

/THREAD

You're right,  if I can't afford a few hundred bucks for some tubing I can't afford to go racing..
   That's not the issue here but, this really isn't the place to discuss it.. Jay would like engineering facts prior to making a decision I'm sure.  Heck I've already listed reasons it shouldn't be allowed (I'll wait go back and find them if you are interested)  and those reasons have nothing to do with safety. 
  The funny part about these sites is that every person has their opinion and it's remarkable that opinions vary so wildly..
  It's like trying hold a discussion with a crowd..

Here's the rule:
"Rollbar Tubing and Padding: Minimum tubing size for cars weighing under 3000 pounds as raced is 1.50" x .120". Properly bent, racecar-grade and -quality tubing is mandatory: no stretched or crushed bends allowed."

See the part about 1.5x120 racecar quality tube?

Goto a race car supply shop, like jerrybickel.com
and buy some 1.5x.120 cr-mo roll cage tube and build a cage.
To avoid confusion, here's the link:
1.5x.120Cr-Mo rollcage tube

Done.

Tube is Tube, its all measured the same, just material and method of manufacture changes.  DOM or ERW might be harder to find in certain sizes that Chromo is popular in but its around.

Come on John, It was just getting started.

More than a dozen posts and several days ago you'll see my response which was I guess if I can't afford a few hundred bucks for some  tubing I can't afford to go racing..
 
Rule of thumb.. read what is posted, do not assume anything!
  Now I've controlled my anger at your offencive response.
  But if your a real man you'll go back, confirm what I just said and then apologize..

The inspectors have a drill and will make a hole if you dont already have one.