Roadster Roll Over Protection

[Huz-Z]

Guys, here is a local news article on an accident involving a Mazda Miata that rolled over, killing the driver:

http://www.cbc.ca/canada/newfoundlan...fatal-118.html

In a picture on the local TV news last night, it seems that the "roll bars" on the Miata collapsed completely, and the windshield frame also partially collapsed.

With respect to the BMW Z4, its my understanding that the roll over protection in our cars is much more robust. I've seen comments and pictures where its clear that the Z4 roll bars are welded structural elements that are designed to not collapse in a roll over. Does anyone know how the Z4's roll over protection system may have performed in actual crashes?

Cheers and safe driving.

[SHEEDI]

there you go.

http://www.nhtsa.gov/About+NHTSA/Pre...#39;s+Web+Site

[MinneapolisJeff]

the Miata has roll bars?

[Huz-Z]

Originally Posted by jman1975

the Miata has roll bars?

On later models, yes. But I think they are largely decorative.

[CalRick]

Originally Posted by Soomro

there you go.

http://www.nhtsa.gov/About+NHTSA/Pre...#39;s+Web+Site

I believe all that the NHTSA rates is resistance to rollover rather than how well the car survives a rollover; so between its low CG and stability control the Z rates quite well in avoiding rollover. I haven't seen any objective test data on how well it holds up if it does roll, or how it compares to other roadsters.

[CalRick]

Originally Posted by Huz-Z

On later models, yes. But I think they are largely decorative.

It doesn't look like the car in the CBC picture had rollbars on it; with earlier models that didn't have factory rollbars it's anybody's guess as to how well aftermarket bars will work. I would expect later models where rollbars are designed into the structure of the car that they would work about as well as those on the Z.

[Nhopkins1394]

I'm 6 ft 6 inches tall.
My head is at least 3 inches taller than my roll bars.
I know I'm dead in a roll-over accident!

Oh, and when the side airbag goes off...it'll probably break my left side ribs. Lot's of help there , too.

But man is this car fun to drive. Just need to be careful.

[azadian2b]

Originally Posted by Nhopkins1394

I'm 6 ft 6 inches tall.
My head is at least 3 inches taller than my roll bars.
I know I'm dead in a roll-over accident!

Oh, and when the side airbag goes off...it'll probably break my left side ribs. Lot's of help there , too.

But man is this car fun to drive. Just need to be careful.

Slouch 3 inches if you're ever in a roll over accident?

[45ACP]

I thought the roll bars pop up even more in event of a rollover?

[ZStig]

lol, not like gravity isn't stronger than your slouching muscles....


I've seen those miata pics, and seen a pic of a rolled z4. the z4 retains its shape

[ZZZZ]

Originally Posted by 45ACP

I thought the roll bars pop up even more in event of a rollover?

That's on the 3-series vehicles from the 90's to present. Usually integrated into the rear head rests. Z4 has passive rollover protection in the form of reinforced A pillars (notice how chunky those things are?), and the rollover hoops behind the driver and passenger that are welded directly to the frame of the vehicle. In the even of a rollover, the hoops and a-pillars should keep the vehicle off the road enough that the occupants inside the cabin don't directly hit the cement. Unless you're 6'6" then wear a racing helmet.

Also on the 3-series cars, when the car detects a rollover the hazards automatically turn on when the vehicle is upside down in mid-air, the airbags deploy, ignition shuts off, fuel is cut off, and if equipped with a SOS feature, the car calls for help. Not sure how many of these features ended up on the Z4 though.

Here is a photo of a Z4 that rolled over 3 times. Unfortunately I do not know the speed of the accident, or which direction the rollover happened, or if it flipped on cement or grass/dirt. Looks like it landed in soft-earth though, which may attribute to the minimal visible damage. But the structure seems to have held up well regardless. Drivers A-pillar bent a little.

[ZZZZ]

Originally Posted by jman1975

the Miata has roll bars?

The one in the picture doesn't seem to have any roll bars.

[Huz-Z]

Originally Posted by ZZZZ

The one in the picture doesn't seem to have any roll bars.

Its kinda hard to know for sure as the roof was up at the time so you can't really see if there was a roll bar(s). However, I have seen a number of older Miatas going around town and they have a roll bar behind the headrest. I just don't know if they are functional or just a styling element.

I've scanned Mazda's website re the MX-5 and it talks about numerous safety features of the car but I haven't seen anything about roll bars in the safety section. I've called the local dealer to find out more. I'll let you know what they say.

ZZZZZ: its good to see that the Z4 in the picture held together nicely!

[bdejong11129]

Originally Posted by Roffle Waffle

lol, not like gravity isn't stronger than your slouching muscles....


I've seen those miata pics, and seen a pic of a rolled z4. the z4 retains its shape

I think its more the centrifugal force that will propel you in the opposite direction of your slouching muscles.

My other vehicle is a motorcycle so either way I am going to have a boo boo..but for the enjoyment they bring I dont care(yet).

[azadian2b]

Any time anyone mentions centrifugal force all I can think of is this: http://xkcd.com/123/

Anyway the comment was being snarky. There is no way I'd expect anyone to have the body control to slouch 3 inches in an accident where their car is ROLLING OVER.

[Swashplate]

LOL priceless.

[bdejong11129]

Originally Posted by azadian2b

Any time anyone mentions centrifugal force all I can think of is this: http://xkcd.com/123/

Anyway the comment was being snarky. There is no way I'd expect anyone to have the body control to slouch 3 inches in an accident where their car is ROLLING OVER.

Well of couse is was meant to be snarky as was my reply... Love the linked comic as well, nothing better than learning through comic strips or better yet Wikipedia...

http://en.wikipedia.org/wiki/Centrifugal_force

[epbrown]

The chief source of roll-over protection is the windshield, which is crazy reinforced in the Z4, and built to support twice the weight of the car while upside down. The chief guage of its strength is the windshield - I haven't seen a Z4 rolled where the A-pillars deformed enough to break out the glass.

[ZStig]

Originally Posted by bdejong11129

I think its more the centrifugal force that will propel you in the opposite direction of your slouching muscles.

My other vehicle is a motorcycle so either way I am going to have a boo boo..but for the enjoyment they bring I dont care(yet).

yeah thats what I meant

[pokeybritches]

The thing that concerns me the most in that rolled Z picture would be the seat. I guess it's deformed in the proper direction (away from the shoulder seat belt connecting point so that the driver was forced towards the center of the car). I'd rather see it maintain its position, but then again I'm not the guy that was in the crash...

[Huz-Z]

The salesperson from Mazda just called me to say that on the Miata MX-5, the roll bars are decorative and have no real safety function.

I wonder how many folks drive those things and are of the mistaken belief that the roll bars will provide some protection in a roll-over?

Thank God I have a Z4!!!!!