Roll cage tubing - wall thickness quick please

[Carl Johansson]

guys,
I have to order my steel tubing for my roll cage -  GT class over 2500lbs.  I can't find my rule book -  had it yesterday - now I can't find the dang thing.

wall thickness on tubing -  is it .120? (mild steel?)  or is it .095

please hurry -  I'm melting!!!

[Glen]

1-5/8 x .120 wall. Don't know how fast you plan to go but why have to upgrade later.
Glen

[Carl Johansson]

1-5/8 x .120 wall. Don't know how fast you plan to go but why have to upgrade later.
Glen

Thanks Glen, I'll actually be going 1 3/4 X .120.
Appreciate the input!

[Glen]

the 1-5/8 was the minimum good luck on the project. send some pictures of what you are doing

Glen

[interested bystander]

You may not  have to worry about a sonic tester with SCTA/BNI, et al, but NHRA in their infinite ignorance will only accept .120 wall (mild steel)l that is .118 or thicker, wheras INDUSTRY STANDARD is something like min .112 to max .125 .
This is for HREW, have not researched DOM.

NHRA caused one high volume kit racecar builder out of business, or just disgusted him so that he bailed, when they ruled on that and caused everyone else to purchase .134 wall to this day .

Use your own judgement, get receipts for your log book from the supplier, etc.

[dwarner]

The SCTA rulebook calls for a nominal wall of .120" because of the variances in the manufacturing process.

DW

[John Nimphius]

In a tighter radius bend, like the top of a roll cage, does the thinning of the outer diameter ever require going to a higher wall thickness to insure passing tech?

John

[Rick Byrnes]

Carl
Use the biggest thickest, bestest you can find/afford.
LSR is the only racing where a little more weight is not your enemy.  Your car has the potential of being way faster and heavier than you think.

Be safe and have fun.

Rick

[Carl Johansson]

I agree with you Rick -  to a point -  The problem with fitting a roll cage inside a production vehicle is that it tends to cut down your mobility -  some controls or things that you need get "shut off" by the cage -  unless it's designed very well -  and you are lucky -  going with bigger OD tubing will create a head clearance issue (it's already dicey) and make using a clutch almost impossible.   In a ground up build you do the cage and work around it -  in a production based vehicle - the cage becomes a real pain in the parachute if you get my drift!

Carl Johansson

[Freud]

Carl, let your wife chose the wall thickness. Then you will know exactly where you stand in your LSR adventure.
FREUD

[Speed Limit 1000]

Freud, Most wives would let you use tubes you can get from SSS

[JackD]

Roll bar tubing is measured by the outside diameter and independent of the wall thickness.
Thicker wall tubing does not take up more room in a racer.
Steel pipe is measured by the inside diameter and again independent of the wall thickness.
Nominal wall thickness as a specification makes more sence than an unrealistic minimum.
Ya gotta give SCTA credit for that.

[Carl Johansson]

Roll bar tubing is measured by the outside diameter and independent of the wall thickness.
Thicker wall tubing does not take up more room in a racer.
Steel pipe is measured by the inside diameter and again independent of the wall thickness.
Nominal wall thickness as a specification makes more sence than an unrealistic minimum.
Ya gotta give SCTA credit for that.

Hey Jack,
If this was a response to my answer to Rick -  please allow me to clarify what I meant.  Tubing wall thickness does not vary the tubing OD -  I know that.  However Rick was referring to the "Biggest" I could find -  I took that to be OD.  If he were to reference thickest I could find -  I would have assumed he was talking about wall thickness.

Can I post pictures here?  if so I'll put up photos of the cage we built!

Carl Johansson

[JackD]

See, now everybody is on the same page I hope.