removable roll bars/cages
 

i have a generally poor impression of bolt-in roll bars, or bars that have sections removed by way of a single slide bolt.

however one construct that i have never seen discussed is illustrated in the photo below, and i'm trying to figure out if there is any merit to it.

the tubes will be of adequate (if not more than adequate) thickness, with properly made threads, and the nut made from proper material.

in either case, i can't imagine it being any worse than the slide-bolt designs.

EDIT: i was just talking to a cage buildier and i guess i should clarify that the "GIANT NUT" will be a tube of a foot-foot and a half long, with inside threading. But he says the industry average of "tube in a tube with 2 bolts in different directions" seems to be legit and no body really complains


would like to hear your general comments on the idea

Why not just use a larger diameter tube of approx 8-9" in length to connect them and then have two bolts to hold that in place? Seems easier.

that's the thing about slide bolts

i can be entirely wrong, but arn't the forces then concentrated on that single bolt, rather than being spread over the area of the threaded nut

I'm not seeing the point. Most people with bolt in cages get them because they don't want to permanently weld the cage to the chassis IMO. Do others agree?

This does not solve that problem.

thinking more of a roll bar

you weld in the outside perimeter, but allow the center X to be removed at will.

same for the door reinforcements.

having said that, i think the rollover protection qualities of modern cars are pretty awesome, so i wouldn't be too worried about (considering i won't be doing door to door racing)



EDIT: i was just talking to a cage buildier and i guess i should clarify that the "GIANT NUT" will be a tube of a foot-foot and a half long, with inside threading. But he says the industry average of "tube in a tube with 2 bolts in different directions" seems to be legit and no body really complains

The idea behind the 8-9" steel bar over the joint of the two bars is to help spread the load. In my old bolt in Kirk Racing cage it used two grade 8 bolts. I never tested it (thankfully) but I wasn't too worried.

However in anything but a race car I wouldn't bother with a cage (4 point is fine though) and in a race car I wouldn't bother with a bolt in :)

Why remove the cross brace and diagonal? The reasoning for having those be removable has always escaped me. With a 4 point installed you should *never* have people in the back anyways so access doesn't seem to be that badly needed?

And he's right, that's how mine was, and maybe it was a foot long.. I sold that cage 8 years ago so that level of detail escapes me lol

i never understood the logic behind people being afraid of hitting the steel tubes, i mean if you're gonna hit something, you're gonna hit something (ie, the car's interior wall/glass window/rear window, etc.

plus, it depends on how your route the other components.

but one plus of having the diagonal removed for daily driving is reduced cop attention.

Because people would rather hit their head on a padded piece of soft plastic than a hard steel tube? At high impact the little bit of foam wrapped around the roll cage (which is much closer to your head) does little.

Personally I don't think cages should be in street cars (unless you drive around with a helmet all the time, like the Stig...).

Exactly. The car's interior is a much softer surface that's farther away from you that the down tubes, main hoop, etc are. They flex, the steel bars do not.

Foam on a rollcage won't protect an otherwise unprotected head at all. I used to be one of those idiots that drove a caged car on the street, I would NEVER consider doing so now. Granted I was 23 or so when I did.

As for police attention, even driving a honda and living on one of the main street racing roads (which really sucked ass, especially in combination with what I drove, I had to avoid people following me CONSTANTLY.. fucking dumbass street racers) I never once got pulled over by the cops, even when using r comps, hawk blues that shot sparks out and a side pipe. Maybe cops around me didn't care, but I doubt a rollbar is much of an issue.

Have you ever hit your head, hard, against a steel tube? A rollbar with no helmet and no SFI rated rollbar padding is a recipe for a cracked skull.

SFI padding isn't designed to stop a cracked skull...it's intended to prevent cracking a helmet.

The sleeve & bolt cages are acceptable in most HPDE settings. The threaded coupler looks like it would be a royal pain in the ass to use and is probably less structurally sound than the dual-perpendicular bolts in a sleeve method.

i am i no way denying that

but people die just the same from hitting their heads against windows, steering wheels and interior bits (even if they are designed somewhat to absorb impact)

yes, the cars carcass is designed to flex... when it hits a concrete wall, i question the statement that it is designed to flex when a 20lb sack of flesh is supposed to hit it from the inside.

and will argue that the "foam padding" is in no way worse than the 2mm plastic used to wrap around the interior of your car.


having said all that, i have been participating in motorsports for over 6 years and am still driving stock (see sig), however there are times when i think about my safety a little too much and start thinking of something along the lines of a roll bar... :thumbsup:

Yes people die from everything. That doesn't mean that INCREASING the odds of someone dying because of your poor judgement is acceptable though.

I'm all for safety in motorsports, just not at the expense of others who happen to be in your car.