Roll Bar: Hard Dog Sport Double Diagonal


Pros: Should protect my noggin if the unthinkable should ever happen, increased chassis stiffness, makes your Miata look tough
Cons: Must do some irreversible modifications to the car, seat belt retraction is affected.

I was kind of a guinea pig for this product, I was one of the first people to install this roll bar in a 2001 Miata. There was nothing to worry about though, it fits 2001 and later Miatas with no problems.

I bought a roll bar to protect my head. Although I like to drive aggressively which could warrant a roll bar, there are also lots of other drivers out there and you never know what they are going to do. Having a roll bar gave me some peace of mind; they definitely aren’t for everyone but it fit my needs perfectly. I have been asked many times why I chose the Sport model over the Hard Core and here is why. I have no doubts of the sport models strength, I don’t ever intend on doing any SCCA racing so I did not need to meet their requirements, I eventually want to get a hard top, the height of the bar wasn’t an issue to me because I am only 5’9″, and the fact that it was cheaper didn’t hurt either. You can’t really go wrong either way for you Miata, it comes down to what you want and need for your Miata.

I have also been asked repeatedly how the bar affects seat travel, so here is the answer and how I came to it. First I put the seat back all the way forward and pushed it back to the first click so that the seat back was vertical. Then I slid the seat bottom all the way back. I then proceeded to count the clicks of the seat back until it could go no further back. The count was 8 clicks. So, with the seat bottom all the way back and with the seat back starting from vertical, you can tilt the seat back 8 clicks until it hits the roll bar. Hope this helps anyone considering the HDSDD in their 2001 Miata.

All right, on with the install.

I did the install over at a friend’s house and getting the bar over to his house was a bit of a challenge. This is how I did it.

The first thing you need to do is take apart your Miata. Remove the wind blocker, trim panels, carpet and the metal plate that makes up the rear deck. I also removed my seats which I highly suggest doing. The instructions say to trim the package shelf. I did not do this; it made the drilling a little awkward but kept me from cutting up my Miata anymore than necessary. The picture on the left shows the car with everything out.

After everything is out, you are ready to put the roll bar in. Care is to be taken with the rear leg foot braces so that you do not cut any of the wires running in the tunnels. The lower mounting points will align with the lower seat belt reel bolt holes (see pic on below left). The roll bar plates fit against the seat belt reels which stay in their original location but do not use the original spacers (see pic on below right). Once the Bar and the reels are in position, lightly tighten the seat belt reel mounting plate bolts from the hardware kit; make sure that your belts are on the inside of the roll bar, otherwise you will be screwed later on.

Miata Hard dog sport double diagnol roll bar Miata Hard dog sport double diagnol roll bar

Now it’s time to jack up the rear of the car and put it on jack stands so that you can install the backing plates underneath the car. So go ahead and remove the rear wheels. You will need to remove the plastic splash guards that are held on by these funky fasteners so that you can remove the wheels. I managed to break one of these while removing them (stupid mistake). When this is done, you will have the picture below.

Now comes the scary part. Go get your drill!! I did get the 12″ bit that Hard Dog says is required. I’m not sure that I needed one quite so long but it didn’t hurt. There are a total of twelve holes you need to drill. Three for each of the front mounting brackets and three for each of the rear leg foot braces. The drilling only hurts the first time and is pretty easy to do, don’t worry your Miata won’t hold it against you. The front legs especially are easy, just drill from the front and your good to go. The back ones are a little trickier. What I did was drill one hole from inside the car. I wasn’t able to get the drill completely vertical but that was nothing a dremel couldn’t fix. After I drilled one hole from the top, I threaded a bolt through and put the lower plate on from within the rear wheel well. After that was in I drilled the remaining holes from the wheel well using the plate as a template.

The pic on the left is for the front brace and the one on the right is for the rear legs.

Miata Hard dog sport double diagnol roll bar
Miata Hard dog sport double diagnol roll bar

Now you can go ahead and tighten all your bolts down because the roll bar is in!! Now comes the tedious part, putting it all back together. First you need to trim the rear deck. This is easy. I wasn’t real anal about this because you’re never going to see it. I just used some tin snips and cut out some notches as seen in the pic on the right.

The next part is a little scary also. Trying to put all the interior trim pieces back in means that you have to cut them in half. Once I figured out where I needed to cut, it was a piece of cake. I just used a dremel with a cutting wheel and took my time. The driver’s side can be seen on the left and the passenger side on the left.

Miata Hard dog sport double diagnol roll barMiata Hard dog sport double diagnol roll bar

Here you can see the rubber trim piece that I added to the interior panel to give it that finished look. What I used was door trim that is used on the edge of your doors so that you don’t give cars door dings. On the left is the passenger’s side, on the right the driver’s side. This really made an amazing difference in the looks of the install and I highly suggest doing something similar.

Miata Hard dog sport double diagnol roll bar Miata Hard dog sport double diagnol roll bar

And here’s the roll bar in the car; and as you can see, it clears the 2001 seats just fine. In the pics the driver’s seat is in the position that I drive in (I’m 5’9″) and the passenger’s seat is all the way back and reclining until it hits the diagonal.

The roll bar really does stiffen up the Miatas chassis, and makes your little Miata look like a manly beast, no more girly car comments with a roll bar in your Miata!

If you’ve got any questions or comments about this article please let me know by filling out the form below.

Comments & Questions

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12 Questions/Comments/Trackbacks so far

  1. Posted by: ht
    November 22, 2009 2:00 pm

    going to buy a 2001. how much is the roll bar? how much will it cost to pay someone to install? i hear these cars shake at 65moh, what can i buy to help that(rollbar, sway bar)?? how many miles can i get outta this car? I have to buy an automatic(any problems with those)?? i live in Pa. how do they do in the snow? do they start up when its cold?? ——————————————should i buy a rollbar on EBAY??–alot of those say rollbars but are only sport bars…. IS THIS CAR good to buy if its gonna be my only car??—————nice website!!

  2. Posted by: Moe
    November 22, 2009 5:42 pm

    That’s a whole lot of questions you asked there.

    The bar costs about $385
    I don’t know what it would cost to have someone install it, I did it myself.
    I’ve never experienced any shaking of the car at 65mph, or any speed for that matter.
    Miatas tend to be very reliable, so you should get a lot of miles out of it.
    Other than other Miata drivers laughing at you, there are no problems with the automatics that I am aware of.
    I live in CA so I have no experience with the car in the snow/cold.
    As for buying on ebay, if the rollbar is a good one and you trust the seller, then go ahead and buy it on ebay.
    I love my car, but only you can answer if it’s going to be a good car for you as your only car.

    You should really go to and do some reading, especially on their forum.

  3. Posted by: professional nurse
    May 10, 2010 9:34 am

    i really like it, it looks good and distinguishs your miata wich at times has been called girly. how much did it effect the seat belt retraction?

  4. Posted by: Bobby
    January 26, 2011 11:49 pm

    I’ve been thinking about getting one but I didnt realize how much destruction I’d have to do 🙁

    Anyway, I live in Kansas City so I thought I’d shed some light on the snow question. Over the past few weeks, we’ve had about 10 inches of snow. I put 50 lbs of sandbags in my trunk and still had trouble accelerating, and I consider myself an experienced snow driver. ABS is a must. I have normal street tires and they’re fairly old so this may also have had an adverse effect.

  5. Posted by: Seth
    August 21, 2012 12:20 pm

    Does the bar have any effect on rear vision?? I’m really thinking about putting one on my 2001.

  6. Posted by: Moe
    August 21, 2012 12:33 pm

    You can see it in the rear view mirror but after having it in the car for a couple weeks you don’t really notice it at all. I personally have no issues with the bar obstructing my rear vision.

  7. Posted by: Jesse
    March 16, 2014 12:58 pm

    Thank you for counting the recline clicks! Do you think the safety padding would change the recline? I don’t see any padding on your bar.

    I just started researching roll bars seriously after realizing that I barely fit into mine while slouching, even after removing seat foam. Being 6’3″ sucks for driving a Miata! Having a roll bar is probably impossible unless I install a racing seat on the floor.


  8. Posted by: Moe
    March 16, 2014 1:37 pm

    Jesse, you didn’t say what year your car is. The 2001 introduced new seats that are taller. Safety foam may have some effect on reclining, I can’t say for sure though. I am only 5’9″.

    I would suggest posting over at and seeing what other tall people have done. I am sure there is someone at least as tall as your on there.

  9. Posted by: Jesse
    March 16, 2014 2:00 pm

    I too have a 2001. At least I don’t have to worry about a broken neck like the ’99-’00 seats! It looks like roll bar padding might interfere with seat travel at the upper corners, especially with a vinyl cover over the pad.

    I plan on contacting some of the autocross racers in my area for better ideas and real life comfort testing. After reading your description I went out to my Miata that is still in winter storage to test my seat position. Lately I’ve been focusing on posture and never realized how much I’ve been slouching just to squeeze under the roof when the top is up. I am searching seat options and may try a more aggressive foamectomy. Mine has tan/beige leather seats and I’d really like to find something similar in color. Tan Lotus seats are impossible to find and racing seats aren’t daily driver friendly because they make ingress/egress more difficult. As you can see my situation is extremely difficult to solve but not enough to give up and sell the car!

  10. Posted by: Kevin McGuire
    March 21, 2014 5:44 pm

    I have a 1991 Miata and am interested in a street rollbar for it. I have built scca approved roll cages in the past with low carbon dom steel. what can you supply that would fit under the convertible roof. Thx Kevin McGuire

  11. Posted by: Moe
    March 22, 2014 3:43 pm

    I can’t supply you with anything. I am just some guy with a Miata. I don’t sell anything.

  12. Posted by: Mike
    July 6, 2014 7:57 pm

    Thanks for the tip on the door trim. I used it on the panels and I think it looks amazing. Plus it hides my ugly uneven trimming. 🙂