Atom rollover, rollbar collapse, kills occupants? Ever happened?

[MadMaxAtom]

I agree,the factory central air box "hoop" is not to be considered adequate roll over protection,but the optional Ariel factory 4 point roll bar is more than up to the task for such a light car. I feel the SRA setup is well beyond what is necessary and is ..."useless extra weight"...

[777]

Pretty sure it would flatten in a rollover without a lateral cross brace. Tying it to the air box hoop would be better than nothing….. just my opinion.

[Rick R]

Pretty sure it would flatten in a rollover without a lateral cross brace. Tying it to the air box hoop would be better than nothing….. just my opinion.

+1. Lateral cross brace makes a lot of difference. The SRA looks quite crappy in all fairness but I wouldn't feel safe tracking the atom without a cage.

[MadMaxAtom]

"Pretty sure it would flatten in a rollover" I'm sure you are wrong,however,feel free to test one.
The factory optional 4 point track bar does tie into the "hoop" and supports it laterally. I have NO issues tracking my Atoms without adding additional weight/tubes/complexity.…although I come from a bike background where you have NO protection other than a helmet,leathers and skill,so in my opinion something is a LOT better than nothing. If you feel safe in a heavier cage,more power to you.

Calling the SRA cage "crappy" is just plain stupidity. If you are that nervous about a crash,maybe you should stick to tiddly winks..

Think of it this way..you could brace and tube an airplane cockpit to protect the occupants in a crash,however it would be so damn heavy it could not get off the ground! That's why there is basically NO safety "cage" in an airplane,other than what is required structurally to support it to fly.They are not designed to crash well.
I have to laugh when I see (or have to squeeze into) a small car with a mammoth jungle-gym welded inside,adding several hundreds of pounds..especially street cars,which then handle and wallow about with all that extra ballast,like a garbage truck..in the name of safety!

Below are the tubing requirements for SCCA competition cars..The optional track roll hoop on the 1,350lb. Atom is 2", .120 DOM,so WAY over built.

Vehicle Weight Material
Without Driver Mild Steel Alloy Steel
Up to 1500 lbs. 1.375 x .095 1.375 x .080
1500-2500 lbs. 1.50 x .095 1.375 x .095
Over 2500 lbs. 1.50 x .120, 1.50 x .095
1.625 x .120,
or 1.75 x .095
C. Minimum tubing sizes for (all Showroom Stock, Touring and
Improved Touring Category automobiles registered after June
1, 1994) for all required roll cage elements (All dimensions in
inches):
Up to 1500 lbs 1.375 x .095 DOM / Seamless / Alloy
1501-2200 lbs 1.500 x .095 DOM / Seamless / Alloy
or 1.500 x .120 ERW
2201-3000 lbs 1.500 x .120 DOM / Seamless / Alloy
1.625 x .120 DOM / Seamless / Alloy
1.750 x .095 DOM / Seamless / Alloy
or 1.750 x .120 ERW
(American Sedans may construct to these
specifications regardless of weight.)

3001-4000 lbs 1.750 x .120 DOM / Seamless / Alloy - No
ERW
Over 4000 lbs 2.000 x .120 DOM / Seamless / Alloy - No
ERW
Main hoop: 4 bends maximum, totaling 180 degrees ± 10
degrees.
Front hoop: 4 bends maximum or Front downtubes: 2 bends
maximum.
Rear hoop supports: No bends.
If any of the above bend requirements cannot be met, all
components of the roll cage shall be fabricated from the tubing
size(s) listed for the next heavier category of automobiles.
D. For purposes of determining tubing sizes, the vehicle weight
is as raced without fuel and driver. The minus tolerance for
wall thickness should not be less than .010" below the nominal
thickness. Improved Touring roll cage tubing sizes are to be
calculated based on the published vehicle weight minus 180
lbs.
E. An inspection hole at least 3/16 inch diameter shall be drilled
in a non-critical area of all tubes with a specified size to
facilitate verification of wall thickness.

[Rick R]

Calling the SRA cage "crappy" is just plain stupidity. If you are that nervous about a crash,maybe you should stick to tiddly winks..

Dude, chillax...
My bad for wording my post poorly, I didn't mean I don't think it's robust enough, I meant it looks exceedingly unsightly. Poor aesthetics aside, that's what I want on the car if I do buy an Atom. I'd feel very safe and comfortable tracking an SRA, while I wouldn't if I were riding in a normal car with a roll hoop. See my earlier posts where I was wondering if it could be retrofitted to a straight Atom. Maybe that's just me, but I don't think I'd be able to push for 10/10 without that level of protection.

[777]

"The factory optional 4 point track bar does tie into the "hoop" and supports it laterally."

Hi Max, I had an Atom 3 with the 4 point roll bar. It wasn't tied into the hoop. Has the factory made a mod?
I thought about drilling and bolting the two together but I didn't because it still wouldn't pass SCCA tech. So I bought a Spec Racer.

SCCA GCR page 113
2. Main Hoop Bracing
a. Main hoops shall incorporate a diagonal brace. The brace shall either be in the plane of the main hoop, or extend from the top of one rear brace (described in 9.4.B.2.c) to the bottom of the opposite rear brace. Automobiles with mid mounted engines can have the lower mounting point attach to the frame of the automobile within six inches of the main hoop. In the case of braces in the plane of the main hoop, the brace must span at least 50% of the width of the main hoop, and at least 75% of the height of the main hoop as shown in figure 12.

If you'd like to talk aircraft safety, check my username. Pilots are trained to avoid trouble. You don't exceed design limitations if you want to watch your grandchildren grow.

Rick, I agree, the SR is no beauty but that's mostly because it has no tea tray or wings. It's beautiful on the inside (and on the track).

[Terry Kennedy]

"The factory optional 4 point track bar does tie into the "hoop" and supports it laterally."

Hi Max, I had an Atom 3 with the 4 point roll bar. It wasn't tied into the hoop. Has the factory made a mod?

Not this factory, but yes. As part of the changes Brammo made, the rollbar has a plate which attaches to the hoop:



You can tell a Brammo rollbar from a non-Brammo one because the Brammo one is curved across the whole top, while others have straight tubing with a bend in the middle by the hoop.

[MadMaxAtom]

"Pilots are trained to avoid trouble" Ah,one of lifes best philosophies.
I teach all my driving students the same..avoid trouble,however trouble does happen,so we do what is reasonable for potential situations to avoid injury.
Making a 1,350lb car into an armored car is NOT what I consider reasonable. The jungle gym rollcages I have seen...good God!! Sure,maybe for a rally car (maniacs!) but for most on track events for street driven cars..a decent 4 point is fine. Like I have stated...the factory 4 point tied into the "hoop" is more than sufficient for a potential rollover at Atom speeds and given the cars weight.(with proper helmet,harness and arm restraints worn) If anything, the open wheel situation is more dangerous than the potential of a roll.

[777]

Agreed. Tie the 4 point into the hoop to make it a 5 point. Good to go.