Roll bar me - Miata content

I want to add a Roll bar, with padding, to my Mazdaspeed Miata.   

I keep reading different opinions on whether on not its safe to drive on the street with one; that is without a helmet.

I have no danger of my head being higher than the top of the seat as I am 5'-8"  but still, I have the concern, are the naysayers are correct?

Opinions?

And which one should I get?  There are so many choices.   At most I will be autocrossing. 

get it, add padding, stop worrying. You're fine. 

I went with the heart dog Ace double diagonal in my it was the one that was farthest away from my head

I have the Hard Dog single diagonal. It blocks the view from the rearview mirror pretty bad. View with the double diagonals is supposed to be better. Check fitment for hardtop, glass rear window? etc.

I have the Blackbird Fabworx GT3 rollbar. It fit like a glove and looks awesome and rear visibility is still solid, plus Moti from Blackbird is a super nice guy to do business with. Unfortunately it is also quite expensive. I'm a knucklehead and haven't padded my rollbar.

Get good padding - actual rollbar padding, not just armaflex.  You'll be fine.

If my head ever hits this bar, I've got worse problems than that.

That's a Hard Dog Hard Core Hard Top Dual Diagonal, by the way.

The Blackbird bar is beautifully made, but some of their models have gussets at the cross bracing that block my rear view.

Would you rather have your head come in contact with a padded rollbar, or the bumper of a lifted pickup?

Keep in mind SFI padding is not designed to protect your head without a helmet on. 

All Miata roll bars face the same problem: the taller they are, the further forward they have to sit. Or - the further back they are, the shorter they have to be. This is true regardless of the manufacturer, as it's dictated by packaging. I'm going to talk about the Hard Dog models here because I know them, but this will apply to Moti's creations as well. This refers primarily to the NA and NB models, bars for the NC and ND are different due to the different top design and overall packaging.

Head strikes are a real thing. Mike at FM has had a run-in with one. Nobody here has tried rolling a car, but there are a lot of customer testimonials from survivors. Hard Dog will replace the bar for free if you return it for analysis after a roll.

Hard Dog Hard Core: the tallest and thus the further forward. Best protection in a roll, highest probability of head strikes. A little too high for my comfort, I don't recommend this one for non-helmeted use unless you're relatively short. On a related note: the average height of Miata owners appears to be several inches taller than the national average, as they're always 6'3" and trying to get under a roll bar.

Hard Dog Sport (which uses the same geometry as the Hard Core Hard Top aka Sport Fat Boy): a good compromise. Not as tall, not as far forward. The difference between the Sport and the Hard Top/Fat Boy variant is tubing diameter (1.25 vs 1.5") and optional harness attachments.

Hard Dog Ace and Deuce are way far back but pretty short. Better than nothing, for sure, but it's quite possible you'll fail tech at a track day. Basically no chance of a head strike but in a rollover you will not have the same protection.

Are you going to track the car?  If yes, get a roll bar and install 5 point restraints, if not, do not.

You are FAR more likely to be rear ended than to roll a Miata on the street.  Duke, unless you are a little person, you are very likely to hit your head on that bar if you are rear ended.  You move around a lot in an MVA.  Regular seat belts are not enough to secure you adequately to prevent this.

We had a Blackbird single diagonal in our NB, along with race seats and harnesses. Here are a bunch of pictures, both of my daughter (very short) and me (5'8").

Can confirm that the NC bar is a different critter.  I have one and the gyrations required to install it...... well, honsetly I'm not sure how terrible they are, the PO did it.  Unfortunately it appears he did more of a "mock up" exercise and I need to install more bolts and backing plates to finish it. 

Keith, to access the back side of the NC bar is the easiest thing to partly uninstall the soft top and roll it forward?

My old NA had one.  (Hard Dog M2 Dual Diagonal)  My new NB will not.  Here's the pluses and minuses AS I SEE IT.  (I'm not looking to debate anyone on this issue)  Pros:  It may sound stupid, but it looked cool.  In certain types of crashes, I have no doubt it would offer significant protection.  I've seen pics of HARD side hits where HD products kept the side of the car from caving in.  I've also seen several hard rear impacts where the bar appears to have stopped severe intrusion into the rear/trunk of the vehicle.  (Whether that's because of the rear bracing of the bar or just then end of the factory "crumple zones" is a question for an engineer.  I'm not one.  The photos are dramatic, however.)  The benefits in a roll over are well known.  And yes, Miatas do roll over.  A friend of mine flipped his a couple winters ago without a bar.  The crash destroyed his hard top, but fortunately the hard top took the brunt of the flip, but had pretty much disintegrated when the car came to rest.  Had it slid much farther, he would have lost significant pieces of his melon.  In the right circumstances, a roll bar opens up track days and time trial events that you otherwise can't run with a Miata.  It also ads a substantial and noticeable amount of stiffness to the rear of the chassis. 

Now the cons: Mine was padded and covered, but I have no doubt it would have wholloped me good had I ever been hit from behind without the chance to brace.  (I.e. - the average rear-ender in traffic, the most common form of crash)  In some ways a padded bar is softer than a lot of the surfaces in your vehicle, but there is absolutely NO give to it, unlike a dash pad, window trim, etc.  I'm 6'2", the M2 is one of the tallest available bars and there's still no way I would pass the "broomstick test" without substantial modification to the seat.  Even with the well known "foamechtomy", the top of my head was even with the bar.  With a helmet on, it was actually higher than the bar, making the bar somewhat useless.  A roll bar ads a LOT of weight, very high above the CG of the car.  It did bad things to the handling of the car, especially at autocrosses, where minimal weight and quick weight transfer are paramount.  They are . . . not fun to install.  Try working for 8 hours inside the average camping cooler on something heavy, that requires a lot of moving around, and you'll have the basic idea.  (If I had it to do over again, I'd spend the extra hour or two and remove the top, but it's still not a job I'd want to do again)  The loss of seat travel also made the car feel more cramped than it had to.  Since I had the tallest bar available and it still offered little roll over protection, I wouldn't even think about some of the other options Keith described above.  To get any realistic benefit from it (and certainly any shorter/less intrusive bar), I'd need a lowered race seat, which would have killed me in autocross classing and likely made the car less useful as a daily/fun driver.

The end analysis for me:  Not worth it, at least for a tall guy who isn't doing track days.  Your mileage may/will vary. 

I don't own a Miata, but have sat in a few with roll bars. I don't think I would drive one on the street with stock seats. At 6'2" tall, my head is even with the bar and in a rear end accident, the back of my head would be mush. Shorter people might not have that problem, but it would make me nervous. 

I have never been so happy to be short. I’m 5’8”, 220. I fit snug, but I fit. I have the hard dog hard bar. It was cheaper, does provide something, I don’t plan on track days, and installing it was a breeze. As others have said, more serious vehicle, then yes, I would get a more serious bar, but for street driving and autocross, it’s perfect. I fit with a helmet. Broomstick tested. I’m also “long torso’d” whatever that is...

FYI the hard bar is a Sport without the rear braces. 

KyAllroad (Jeremy) said:

Can confirm that the NC bar is a different critter.  I have one and the gyrations required to install it...... well, honsetly I'm not sure how terrible they are, the PO did it.  Unfortunately it appears he did more of a "mock up" exercise and I need to install more bolts and backing plates to finish it. 

Keith, to access the back side of the NC bar is the easiest thing to partly uninstall the soft top and roll it forward?

Honestly, I've never personally installed an NC bar. I don't know.

About those who are looking for head clearance: the "foamectomy" suggested on forums etc is the least effort to do, and is usually oversimplified. Better way is to actually shape the seat foam. If done properly, it will be both more comfortable and more supportive as well as being lower. You can also do a few other things to lower the seat.

I have a single diagonal in my NB. It makes the top nearly impossible to pull up while belted in. It cuts off the top half of my rear vision, or the middle if I adjust the mirror. It also reduces available space on the deck. I'm under 6' and I padded the bar, but it is a little too close to the seat for comfort. The bar looks cool and it's a great way to haul a set of 4 tires. If I could swap for any other bar I'd get one that sits farther back. Otherwise for me, it's pretty much a wash. I'd be happy with or without one.

About those single diagonal comments - the double diagonal was introduced about 20 years ago, and has become by far the most popular variant. Rear vision is a big factor.