NA/NB Frame Rail Braces & Cross Brace Kit

Frame Rail Brace & Cross Brace Kit Group Buy

Since the launch of our NA/NB Miata Frame Rail Braces, many customers have since asked if we’ll make additional stiffeners to join the two Frame Rails together. Thanks to your input, we went ahead and designed our new NA/NB Miata Frame Cross Braces.

The Cross Braces are constructed out of the same durable stainless steel as the frame rails, and are designed to bolt right up to your existing R Theory Motorsports Frame Rail Braces. Bolting them to different brand Frame Rail Braces is possible, you might be required to re-drill the bolt holes so everything lines up.

We tested the Cross Braces on our 1997 Miata test car. The car already had R Theory Frame Rail Braces with Backing Plates, Hard Top, Roll Bar, Door Bars, and stitch welding in some areas of the chassis. Even with those existing modifications already on the car, we noticed an increase in chassis rigidity and reduction in vibrations. The suspension was able to do it’s job much more effectively going over bumps and going around corners.

Fitment Notes_

Direct Bolt on for all R Theory Motorsports Frame Rail Braces installed onto the NA/NB chassis.
We added clearances for your exhaust mid pipe. It fit on our prototype car with a large 3” exhaust. If your exhaust hangs unusually low (within 0.5” from the bottom of the frame rails), there might be some fitment issues. But it will fit fine for the majority of single exhaust set ups.
If your exhaust hangs a little bit too low, you can shim the brace lower with spacers. But you can only go so low before you start contacting the fuel/brake lines.
The R Theory Motorsports Frame Cross Brace was designed to sit at the same level as your frame rail braces. So ground clearance is not impacted!
Removal of your heavy OEM bracing might be required on NB2 Miatas (2001-2005).