Mr_Asa
UltimaDork
10/6/22 9:44 a.m.
So Dad wants me to have a rollbar for the Miata. I am not opposed, but now I need to do research.
Chief question is do they work? If so, I assume some work better than others. Is there any data on which is which?
What sort of compromises will I be making with a rollbar in a DD ND?
What do I need to know?
Huggs
New Reader
10/6/22 10:11 a.m.
I just put one in my ND about 100 miles ago. From what I looked up there are really two choices for soft tops, the Blackbird Fabworx (aka Aurora Designs) roll bar and the double diagonal bar from Hard Dog. The Hard Dog was about 850, the Blackbird is almost 1400. You need the double diagonal bar option ticked for Hard Dog for it to be NASA and SCCA compliant, blackbird only has one option and it's compliant. I saw some comments that the backing plates for the feet of the Aurora Designs bar were a bit better engineered, but that was really the only bit that I could find anyone saying that differentiated them. I ended up with the Hardog, as I didn't want to cut on a new car and that's who the shop had a relationship with. Only downside I've had so far is it takes about .2 seconds longer to put up or down the roof.
This is all just research on forums and such, couldn't find any real data or anything. Would be curious if anyone has any or found any. There are also quite a number of arguments out there that the bar is safer on track where a rollover is more possible, but is more dangerous on the street as it's something hard to hit your head on.
I installed an Aurora Designs Blackbird Fabworx RZ roll bar in my NC this spring and the quality and design met expectations. Installation was challenging due to how the forward mounting feet are attached.
A friend purchased the Blackbird RZ roll bar for his ND Miata and I helped him with the install. Same quality construction and design approach. It was considerably easier to install with the biggest pain being trimming all of the plastic interior pieces to look decent after install.
Neither of us have "tested" them yet but I am confident it is an improvement over the factory "hoops".
It's pretty hard to hit your head on an ND bar if your head is still attached to your neck. It's a valid concern on an NA/NB, not on an ND. There aren't really any downsides to a bar in an ND. All of the ND bars have the same problem in that they're not very wide due to the top construction, but that's the car. Installation will always involve trimming plastic bits.
We sell Hard Dog. Moti at Aurora makes beautiful stuff, but I don't believe you get better function for your money, just aesthetics. IIRC the Aurora diagonals used to impinge on some of the interior storage space while the Hard Dog did not, but I don't know if that's still the case.
I don't know if anyone has rolled an ND to test the bar for us.
Mr_Asa
UltimaDork
10/6/22 7:10 p.m.
I would have thought someone with a semi-totaled one would have pulled it over with a winch. If only for the 'gram.
Keith, I don't see the Hard Dog for the ND soft top on the website. I know you guys just redid the website though.
Yeah, there's still a lot of stuff missing. Working hard on restoring it.
Mr_Asa
UltimaDork
10/6/22 8:23 p.m.
In reply to Keith Tanner :
Cool, I'll be patient
Toot
New Reader
10/6/22 9:00 p.m.
In reply to Mr_Asa :
I just installed a nd rf roll bar from flying miata took it out my rf and installed in my regular convetable last week. Took about an hour....didn't put any plastic pieces back in though. There is absolutely no issues daily driving it. When you take out the factory bar you will be surprised how poor the quality is.
Driven5
UberDork
10/7/22 11:58 a.m.
The Hard Dog relies more on the factory structure, bolting the main hoop to factory mount points rather than using backing plates. Not that I've ever heard of somebody being turned away for running one, and while constructed from SCCA compliant material and FAR stronger than stock, this would seemingly make it technically not-SCCA compliant in design... Despite the manufacturer claims.
In addition to the *fully* compliant design and construction, the Blackbird bar also has better rearward visibility, and apparently has some brackets rather than zip ties to help reconnect some of the factory bits. Even if there isn't nearly as much difference in height between the Blackbird and Hard Dog as there is with the NC bars, nobody will get the bar higher than Moti. To me, this all makes the Blackbird better for the track and nicer for the street, and worth the price of admission for it's intended usage.
If that all seems a bit overkill because of zero intentions of HPDE/TT, wanting to keep the budget down, and simplifying installation, I'd probably be looking this direction:
https://auroraautodesign.com/collections/frontpage/products/aurora-auto-design-roadster-hoops-nd-miata-fiat-124
For me personally, the Hard Dog M4 seems to fall a bit short between the two Blackbird options.
I know that Hard Dog worked with a NASA inspector when developing their design, so the "manufacturer claims" are based on those responses. So I wouldn't put scare quotes around "fully compliant".
In reply to Keith Tanner :
If it's good enough for a spaceship, it's good enough for a Miata!
In reply to Keith Tanner :
Getting NASA HPDE approval really isn't saying much. NASA doesn't actually publish any meaningful roll-bar structural design requirements, or even guidelines for that matter. So there's no enforceable consistency in application, and based on the approved bar list has an appreciably lower design threshold than SCCA. No material sizing vs weight minimums, no diagonal bracing requirements, and no attachment minimums. Hell, the lower grade (no diagonal) Autopower Street bars have blanket NASA HPDE approval too, but those aren't exactly held in the highest regard when it comes to track use. That's why I specifically stated SCCA's much more well-vetted and consistently applicable rule compliance. An SCCA compliant roll bar is compliant with every other track organization I'm aware of, but roll bars compliant for other organizations are not necessarily SCCA compliant.
Hard Dog claims SCCA (not just NASA) compliance for the M4, but the bar does not appear to technically do so due to lacking equal size and thickness backing plates on the bolted main hoop mounts. That's not to say it isn't a generally-sufficient design, and mostly-compliant for SCCA to where the tecnically-non-compliant bits are compliant-enough and hidden-enough that nobody will likely send you home for it... But unless SCCA is willing to provide a clarification or variance allowing that attachment method in that application, stating *fully* compliant for the Blackbird bar is still justified IMHO.
For taller people regularly tracking an ND, the Blackbird ND seat mounts that drop the seat by >1" might be another not-cheap but worthwhile upgrade as well.
Driven5 said:
In reply to Keith Tanner :
For taller people regularly tracking an ND, the Blackbird ND seat mounts that drop the seat by >1" might be another not-cheap but worthwhile upgrade as well.
I have that seat mount in my RF and it's worth every penny. Otherwise the rearview mirror creates an ironic forward blind spot.
Mr_Asa
UltimaDork
10/7/22 2:39 p.m.
In reply to maschinenbau :
I am looking forward to going back and forth between your car and mine and seeing what that seat drop feels like. Probably gonna be my first real mod.