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Roll Bar FAQ

Roll Bar FAQ

Why should I install a roll bar?
Miatas have a low center of gravity and are not prone to roll. However unlikely, it can happen and there are plenty of documented cases where people had flipped their car and walked away thanks to their Hard Dog roll bar. There are several other benefits to installing a roll bar. The bar stiffens the chassis quite a bit. Chassis flex in a convertible is inherently an issue and any chassis stiffening will be noticed and appreciated, especially over rough pavement and railroad tracks.

Roll bars are also required or encouraged in most motor sports events. If you plan on doing autocross or track days, a roll bar is a highly recommended.

As a bonus, the appearance of a roll bar in a Miata also lessens the “chick car” persona the Miata has.
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Just how safe is a Miata WITHOUT a roll bar?
Current U.S. law requires that the windshield frame on a convertible must be able to support 1.5 times the weight of the car multiplied by 9.8 and not to exceed 22,240 Newton Meters. Pressure is applied on a braced vehicle to the corner of the cars top. They place the sills or the chassis frame of the vehicle on a rigid horizontal surface, fix the vehicle rigidly in position, close all windows, close and lock all doors, and secure any convertible top or removable roof structure. They then slowly apply pressure to the forward edge of the roof. Both sides are tested. The roof may not move more than 127 mm. (5 in.) Each vehicle model is only required to be tested once. Ref : Part 571.216: Standard No. 216; Roof crush resistance. < >

Let's look at real world scenarios. Many convertible owners drive with the top down. The test also only considers a single static impact on both sides of the vehicle. If you get it going at speed - throw it up in the air and slam it back down on the windshield - now that is a different story. We have seen the results of a Miata in a single rollover (soft roll) come out pretty good. Sure the windshield was bent - but the people were either unhurt (seatbelt engaged at the time of the rollover) or only had minor injuries. Roll it more than that - the windshield gets pretty flat.
Now the question is - who ever plans on rolling their Miata in the first place? Then if they do - only rolling it over once or just rolling it over gently?
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Why should I buy my Hard Dog roll bar from Track Dog Racing?
We are not just a reseller of Miata parts. Each of us have installed Hard Dog roll bars in our personal Miatas and we have installed numerous Hard Dog roll bars in customer cars. We will be there to answer your questions especially if you get stumped installing the roll bar yourself. We can offer advice on which roll bar to chose and why. As a bonus, you get a cool Track Dog Racing roll bar decal when you order from us. This alone is easily worth 10 extra bonus points!
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How difficult is it to install a roll bar?
If you are comfortable with removing your seats, rear deck trim, drilling holes and cutting plastic trim panels installing your roll bar is a good weekend project for the confident DIY enthusiast. Expect at least 8 hours if you never installed one.

You will need a long 3/8” drill bit, interior trim remover tool, air saw or Dremel tool, sockets, wrenches, screwdrivers, jack and jack stands. An assistant for lifting the roll bar in place is also helpful. Power tools also make the job easier.

Get stuck? Contact us and we will be glad to help. 214-340-9797 or
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Where can I get the roll bar installed?
If this is something you don’t want to tackle yourself, we can install it for you if you are in the Dallas/Fort Worth area. If not, check with your local Miata club or a reputable performance shop in your area. However, it is certainly a DIY project for mechanically minded people. Plan on a solid 8 hours with you and a friend.
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How long will it be before I get my roll bar?
For any black powder-coated roll bar, delivery usually is within one week of when the order was placed. Occasionally we catch them in the middle of production of a particular roll bar and delivery can be delayed for 4-5 weeks. We will notify you if this is the case. If you would like to check stock on a particular roll bar, contact us and we can check the inventory.
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Can I ship a roll bar internationally?
It is very cost prohibitive to ship such a large item overseas via traditional shippers. Even Canada is too expensive. Many Canadians have had them shipped to a U.S. shipping receiver and drive across the border to pick it up.

Every time we've checked international shipping for a roll bar, it was as much if not more than the cost of the roll bar itself. One option might be finding a freight forwarding company in the U.S. We would ship to them and then they would send it on a slow boat to you. We have no recommendations for such a service. It was just an idea you might look into.
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What is the difference between a style bar and a roll bar?
As the names implies, a style bar is just that, a bar with style. It offers minimal protection in a roll over and could in fact even lead to additional injuries. This is because style bars are generally attached very superficially at only two points (generally bolted only at the top of the seat belt tower and most will probably break off at the attachment points and bend over, mousetrap style, if very much force is placed on it.
On the other hand a true roll bar will have additional bracing to keep it from bending over or collapsing if lateral force is applied. However, the additional bracing can make it harder to build and install.
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What roll bars meet SCCA guidelines?
We get a lot of calls on this. We called SCCA to find out the truth. According to SCCA, Solo I no longer exists. It was similar to Solo II but at higher speeds. To find out their rules on roll bars we checked out their 2017 SCCA National Solo Rules Book. According to Appendix C on Page 215 the Hard Dog M1 and M2 versions of the Hard Core, Hard Core Hardtop, Sport and the Ace all meet the requirements when equipped with at least one diagonal. We are looking into seeing if any others may also meet the requirements.
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What roll bars meet NASA HPDE guidelines?
According to NASA, the Hard Dog M1 and M2 versions of the Hard Core, Hard Core Hardtop, Sport, the Ace and the center-braced Deuce currently meet or exceed their requirements.
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Does the cross bar that goes between the seat belt towers on 94-97 Miatas have to be removed to install a roll bar?
The bar can be reinstalled after the bar is installed on Hard Dog Hard Core, Sport, Extreme and Hard Bars only. The purpose of this bar was chassis stiffening. The roll bar serves this purpose as well so you will likely see no difference with this bar removed.
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What is the difference between the Sport and the Hard Core?
The M1 and M2 Sport is made of 1½ inch tubing while the M1 and M2 Hard Core is made from 1¾ inch tubing. With the Sport you also have the option of no diagonals, single diagonal or double diagonals and it works with the OEM hardtop. The Hard Core comes standard with a single diagonal and optional double diagonals or X-Brace (on M1 version). The Hard Core will not work with an OEM hardtop unless the hardtop version is specified. All M3 roll bars use 1¾ tubing.
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What is the difference between the M1 and M2 Hard Dog roll bars?
The M1 is designed to work with a plastic rear window and has a standard harness bar. The M2 is designed to work with the OEM and most after-market glass rear windows and has harness tabs in lieu of a harness bar. The M2 will also install on first generation Miatas and is required if you have upgraded to a OEM sized glass rear window.
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How do I know if my after-market glass rear window fits with a roll bar?
32-1/4" wide below the upper corner radius and 14” tall are the magic numbers.

All 1990 - 1997 Miatas came from the factory with a flexible plastic rear window in the convertible top. If your first generation Miata has a glass rear window, it's either aftermarket or a second generation transplant. The basic 1990 - 2005 Miata chassis didn't change allowing the tops and roll bars to interchange. A few quick measurements are very helpful when trying to determine just which bar is compatible. If your glass is larger than the factory NB spec given below, Contact Us for fitment confirmation.

Factory NB (second generation 1999 - 2005) Convertible Top Glass Rear Window Dimensions for comparison:

14" Tall in the center
32.25" Wide across the top measured just below the upper corner radius (approx 2.5" down from the top edge)
Be sure to include the complete assembly including all rigid parts around the edge. Not just the veiwing area.
Width measurements across the bottom of the glass are not of concern."
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Will my factory wind blocker work with all the roll bars?
It depends. The wind blocker with built-in speakers will not work. You will need to remove this item permanently. The one without speakers will work on the Hard Core Hardtop, Sport, and Hard Bar but you may have to leave it up or down and eliminate the folding option. It will not work on the Hard Core, Ace, Deuce or Extreme.
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How much do the roll bars weigh?
The approximate weights are as follows:

Hard Bar 20 pounds.
Hard Bar Sport 35-45 pounds depending on options (diagonal, harness bar) (the M2 is a little lighter because it has shorter rear braces
Hard Dog Deuce/Ace 45 pounds depending on options
Hard Dog Extreme 55 pounds approximately
Hard Core 55 pounds (the M2 is a little lighter because of the harness tabs instead of harness bar)
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Will the diagonal bars for the Sport (optional) or the Hard Core obstruct my rear view?
Yes and No - The single diagonal bar will go right through your field of vision as you look through your rear view mirror. It isn’t bad - just a takes a little getting used to. However, there is also the Double Diagonal version of both bars available. Depending on how tall you are, there may be no obstruction or the cross members may cut off the view of the outer edges of the rear view mirror. The diagonals look to be about 1" in on either side of the mirror diagonally down to the corners, almost a framing effect. After a few days you will not even notice it.
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OK, I’m still confused on what roll bar to get. Can you help?
Sure! Just call us at 214-340-9797 and we will be glad to help you find the right bar for you.
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