I was just talking to a local cage builder this morning and he mentioned some interesting ideas that I wondered if anyone else did and would this be legal. He was telling me about a IT Civic cage he did and how he kept the weight to a minimum by using the specified DOM 1.500x.095 for the main 6 point cage but for the rear x brace, dash bar, and any other optional bars he used a lighter, thiner walled DOM tube. He even mentioned on another cage that he used Chrome Moly for all the "optional bars". Is this standard practice or would this be cheating?

 

It depends on the class - better read the GCR.

I know TransAm used to specify only the main hoop. And there has been at least one fatal accident that may have been avoided had the car not used thin tubing in the door bars.

Either way, I would never recommend skimping on safety. We're not earning any money doing this. Is your life really worth a $4 trophy?

 

thinner tubing for some little reinforcing stuff is ok , I wouldnt think of trying to save weight by going that route on anything structural at all.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crack Monkey &raquo;</TD></TR><TR><TD CLASS="quote">It depends on the class - better read the GCR.

I know TransAm used to specify only the main hoop. And there has been at least one fatal accident that may have been avoided had the car not used thin tubing in the door bars.

Either way, I would never recommend skimping on safety. We're not earning any money doing this. Is your life really worth a $4 trophy?</TD></TR></TABLE>

I totally agree, the main reason I'm looking at getting a custom cage is for the added safety. I would make sure all the "required bars" meet the required size. This would just be for some additional chassis reinforcing.

I just checked the rules they say " All required bars must be made of the same material and meet with at least the minimum specifications for size and thickness." They don't specify anything for the optional bars so I take it as any size tubing and material can be used. Is this correct?

 

Likely not cheating as long as correct tubing is used in specified areas.

The safety issue can be looked at both ways. If you were going to use thicker tube and went with thinner to save weight, it would be looked at as risky. But if you are using thinner tubing where no tubing was originally planned, then you are perceived as smart.

Do what you think is adequate and makes you comfortable.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 6ghatch &raquo;</TD></TR><TR><TD CLASS="quote">I just checked the rules they say " All required bars must be made of the same material and meet with at least the minimum specifications for size and thickness." They don't specify anything for the optional bars so I take it as any size tubing and material can be used. Is this correct?</TD></TR></TABLE>

yes

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 6ghatch &raquo;</TD></TR><TR><TD CLASS="quote">I just checked the rules they say " All required bars must be made of the same material and meet with at least the minimum specifications for size and thickness." They don't specify anything for the optional bars so I take it as any size tubing and material can be used. Is this correct?</TD></TR></TABLE>

Yes. That is how I thought it was worded. So, if you're adding extra bars you may use thinner tubing. I wouldn't use chromo - I think it has to be the same thickness as DOM and is more expensive and harder to weld.

 

sorry, i dont think you guys are right, its been talked about before i think. the exact wording, at least for my 2000 GCR i happen to have handy reads:

10.a.5 ....Any number of additional reinforcing bars are permitted within the structure of the cage, provided they meet the minimum tubing size per GCR Sections 18.1.6.B and C....

you can make bars of different sizes and thicknesss, but they all have to meet the minimum specs. now if its a gusset or corner brace, and its pretty obvious between the difference of a gusset/brace than a reinforcing bar, then im sure a small tube or slab of metal of whatever material is fine.

 

you're thinking wrong , imagine all the required tubes to make the most basic cage , now those have to be 1.5" x .95" , now all the extra little ones you could pick up stiffness with are optional anyway and not limited to those specs.

see ?

 

then what does "additional reinforcing bar" mean?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">10.a.5 ....Any number of additional reinforcing bars are permitted within the structure of the cage, provided they meet the minimum tubing size per GCR Sections 18.1.6.B and C....

you can make bars of different sizes and thicknesss, but they all have to meet the minimum specs. </TD></TR></TABLE>

What is 18.1.6.B and C (GCR not handy at work)?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">then what does "additional reinforcing bar" mean?</TD></TR></TABLE>

an optional part IMHO.

 

optional bar = must meet min specs. whats the confusion?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crack Monkey &raquo;</TD></TR><TR><TD CLASS="quote">

What is 18.1.6.B and C (GCR not handy at work)? </TD></TR></TABLE>
its the page where it defines and lists the material specs (ERW, DOM) and table of weight and min specs for each class that we are all familiar with.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">optional bar = must meet min specs. whats the confusion?</TD></TR></TABLE>

you're the confused one , optional is um , optional.

how can you have a ruling on something that isnt even required ?

 

woah, i just gave THE ruling, 10.a.5, are you just ******* with me? what does that sentence mean to you?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">are you just ******* with me? </TD></TR></TABLE>

nope.

our opinions differ , so be it.

 

its really not a matter of opinion.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">its really not a matter of opinion. </TD></TR></TABLE>

its a matter of you and I interpreting the rules differently and forming an opinion from that , so our opinions differ.

 

I've injected this before-but here goes again. For the safety of my body we custom installed a KIRK cage using 1.75" x .120 DOM tubing. A CRX does NOT require this much meat in the tubing according to the GCR. My fabricator does drag cars as well as other types and is very familiar with ChromeMoly-he said use mild steel to save money. There is no way he would have mixed the materials either. There are engineering variables to condier if you do this. As to what size optional bars can be, think in terms of weight penalty and you will find that the door bars, for example, are not that much heavier between 1.5" and 1.75" and what you gain is additional strength. My oversized cage (8-point) weighs 135 pounds unwelded according to the shipping mainfest.
Our definition of custom is: a main hoop assembly with enough added material on the legs such that you cut it for the tightest/best fit possible. This is also true for the halo components.
Better to be safer than silly. As someone else said - is it worth it for a $4 trophy-I think not.

 

Here are some quotes from NASA CCR:

15.5.17 Additional Reinforcement

Any number of additional reinforcing bars are permitted within the structure of the cage provided that they are installed strictly for safety and do not violate CCR Section #15.5.2 intent. This rule does not permit reinforcements in classes with spec cages. All required bars must be made of the same material and meet with at least the minimum specifications for size and thickness.

Honda Challenge Rules

4.9 Roll Cage

All cage requirements found in the NASA CCR must be met except for the following: 1) Any number of mounting points may be used. 2) Any number of tubes may be used, even for chassis stiffening. 3) Any size mounting plate may be used but must conform to material and minimum specification in NASA CCR. 4) Two forward cage braces per side (total of four) may pass through the firewall and connect at no more than two points in the engine compartment (i.e. strut tower or frame). 5) Tubes may be welded at any contact point, or even be "seem welded." If modification number 4 or 5 above is utilized, an additional 30lb weight penalty will apply. Any tubes that are added shall be inspected for safety reasons. Any tube deemed to be a hazard to the driver must be removed."

 

Looking over those, it appears there is a slight disconnect between the NASA CCR and SCCA GCR. The SCCA GCR seems to require all the tubes to meet the minimum (per 10.a.5, quoted by Tyson above), whereas the NASA CCR seems to require that only the required tubes be of the minimum, and optional braces may be of any material. All this assuming the rules are quoted above in their entirety.

Either way, use the same tubing throughout, the weight you save by skimping is insignificant.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">sorry, i dont think you guys are right, its been talked about before i think. the exact wording, at least for my 2000 GCR i happen to have handy reads:

10.a.5 ....Any number of additional reinforcing bars are permitted within the structure of the cage, provided they meet the minimum tubing size per GCR Sections 18.1.6.B and C....

you can make bars of different sizes and thicknesss, but they all have to meet the minimum specs. now if its a gusset or corner brace, and its pretty obvious between the difference of a gusset/brace than a reinforcing bar, then im sure a small tube or slab of metal of whatever material is fine.</TD></TR></TABLE>

Just to reinforce Tyson's point that he quoted from the 2000 SCCA GCR, it is still the same in 2003 with the one exception that the subsection "B" is no longer referenced.

Rick