I'm currently looking into installing a roll bar for track days and I am interested in getting the Race roll bar with the removable harness and diagonal braces.

After some searching on HT, i found some good pics of the autopower (and kirk) roll bars:

https://honda-tech.com/zerothread?id=198856

I was just wondering if it is possible to use a big clevis pin in place of the bolt that holds the diagonal brace and the harness bar in to make removal and re-installation quicker.

Thanks

 

im sure you "could", but big impacts do weird vibrations at many different modal frequencies. im not sure if i'd be comfortable with that. it certainly isnt spelled out as allowed in any rulebook as an allowable replacement for a proper hardware bolt, but for just a non regulated trackday, thats up to your own discretion.

if you did, i would certainly make sure the cotter pin has absolutely no way of coming off. the standard hairpin cotter pin certainly would not be good enough. i would loop it.

 

thanks for the reply.

Now that I think about it, the clevis pin would probabbly make the whole assembly rattle and annoy the hell outta me.

Would there be any issue if I take the bolts on and off often?

 

I would think taking a bolt on and off would cause undue stress on the threads. If you can I'd bolt it up and keep it there.

 

You'll be fine unbolting it often. You won't be approaching anywhere near the cycle fatigue limits of the bolts. However, I would dump the grade 5 bolts that come with the autopower bar and get some grade 8s at least.

As for the clevis pins, I wouldn't use it. The bars have to work in both compression and extension in an incident. Although the pins may be fine for when the bars are in compression, they won't do anything when the bars are in extension.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94accordsedan &raquo;</TD></TR><TR><TD CLASS="quote">I would think taking a bolt on and off would cause undue stress on the threads. If you can I'd bolt it up and keep it there. </TD></TR></TABLE>

Not if you do not overtorque and stretch/fatigue the bolt you wont.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by s4speed &raquo;</TD></TR><TR><TD CLASS="quote">You'll be fine unbolting it often. You won't be approaching anywhere near the cycle fatigue limits of the bolts. However, I would dump the grade 5 bolts that come with the autopower bar and get some grade 8s at least.
</TD></TR></TABLE>

Got it, I'm suprised they come with only Grade 5 bolts.

I just hope I don't cross thread them one day. I hate pulling out my tap set.

 

Just curious why you would want to occasionally remove the crossbar and harness bar? Forget about backseat passengers even with these removed.

 

I have no authoritative data on this, but:::

My Autopower (94+ Integra) Roll Bar came with the diagonal welded, no bolts. November 2004. Older ones came with bolted diagonals.

Such as: http://www.sandmracing.com/srollbar.html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by s4speed &raquo;</TD></TR><TR><TD CLASS="quote"> However, I would dump the grade 5 bolts that come with the autopower bar and get some grade 8s at least.
</TD></TR></TABLE>

There's a common misconception that Grade 8's are stronger the Grade 5's.

The fact is, Grade 8's are designed for shear loads, and Grade 5's are designed for tension loads.

Figure out what type of load the fastener is going to be seeing, and use the appropriate grade.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">I have no authoritative data on this, but:::

My Autopower (94+ Integra) Roll Bar came with the diagonal welded, no bolts. November 2004. Older ones came with bolted diagonals.
</TD></TR></TABLE>

Nope, the bolted diagonal/harness bar is an option when ordering it. Nothing more, nothing less.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Nope, the bolted diagonal/harness bar is an option when ordering it. Nothing more, nothing less.</TD></TR></TABLE>

Thanks for the clarification!

 

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

There's a common misconception that Grade 8's are stronger the Grade 5's.

The fact is, Grade 8's are designed for shear loads, and Grade 5's are designed for tension loads.

Figure out what type of load the fastener is going to be seeing, and use the appropriate grade.</TD></TR></TABLE>

I've never heard that. More over, since the bolts are made of an isotropic material and don't exhibit any special shapes that would indicate one is better in one sort of loading than the other, I find it difficult to believe.

If you look at any chart, you'll see that all the mechanical properties of grade 8 bolts are larger than than grade 5 bolts. And shear strength is generally a function of tensile strength, too.

Not ragging on you. Just think that should be mentioned since I think he really will be better off with grade 8 bolts than grade 5's. Or, since there's only what, 10 bolts, for 10 bucks he can get the premium grade bolts that will hold his cage together in the event of a nuclear explosion.