DIY Miata Roll Bar?

Ah, so all the previous designers of Miata roll bars weren't idiots - it really IS difficult to fit a tall bar under the top The hardtop doesn't give significantly more room.

For different size drivers, try removing the rear seat mounting points but keeping the fronts. This will tilt the seat back a bit, but more importantly it will rise as you slide forward. Gives shorter drivers a taller seating position while putting the tall kids down low.

Keith Tanner wrote: Ah, so all the previous designers of Miata roll bars weren't idiots - it really IS difficult to fit a tall bar under the top

I had a pretty good appreciation of this from the beginning. I'm doing this because I'm cheap, not because I think I can get some result that hasn't been achieved before.

I'll look at trying to lower the rear mounts. If I can squeeze them down just a little bit lower, that would probably do it.

Did you take the bottom cushion out from the seat when you tried the broomstick test? I have to do that on my "Canadian Bride" mounted on Bride LoMax rails to sit low enough...

In reply to BoxheadTim: My daughter mentioned that and she was going to try it to see how much it gained us. Will have to check the mount to see if we can lower the back any. That was my first thought since the seat is very upright, know a tilt angle back will gain us some and be more comfortable.

I do imagine a Miata would look pretty silly with a top that would give us the head room we are trying for. Maybe a Gurney bubble across the whole top for the roll bar. Or maybe the roll bar on top of the top.

Land Rover style, an external cage! I like it.

Sorry, my previous comment about "idiots" came off wrong. I'm only funny to me sometimes.

We pulled those rear mounts on a customer car at his request. It seemed to work for him.

Keith Tanner wrote: Sorry, my previous comment about "idiots" came off wrong. I'm only funny to me sometimes.

I think you're totally right about that though. This is a problem with a lot of tough constraints and a lot of smart people have consider it before. I'm just hoping I can get something that will work out, and be safe, while saving a few bucks for things I can't build myself.

So, this has been going pretty well, though it's been a very time-intensive process.

Here's what I've done so far: Plus the plithns:

Next question: what's the best mounting location for the rear braces (AKA "down tubes")?

I've seen some that are very far back:

And some that are in the middle:

And I think most of the bolt-in bars have them even further forward.

Personally, I don't see the point in putting them any further rearward than the "middle" position which has them right by the shock and subframe bolts, but it does appear that it would make installation somewhat easier.

Anyone have some insight here?

Thanks!

You may find that going too far back is incompatible with the top. I've never had reason to complain about the location used by Hard Dog, although if you're welding instead of bolting you'll have different priorities about ease of access.

I would mount at the rear shock location. Increases chassis rigidity and leaves enough crumple space behind the mount to where a rear end impact shouldn't push the main hoop forward.