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Blackbird Fabworx custom windshield bar review

10K views 46 replies 23 participants last post by  chinamoonman 
#1 · (Edited)
Yesterday I visited Blackbird Fabworx in Northridge, CA to have a custom windshield header bar fabricated for the Pitcrew Roadster. Moti did a great job turning my ideas into reality. This modification essentially turns the existing Hard Dog Hardtop rollbar into a 7-point street semi-cage. Doing this mod required welding captured nuts into the windshield header to distribute the loads over a larger area, as well as fabricating a custom mounting pad and welding it to the main hoop of the roolbar. It does a great job adding stiffness to the body, eliminating all cowl and windshield header vibration. Great job, Moti!




Here are some pictures of the mounting points. Notice the bolts that hold the front of the brace. These are bolted into nuts that have been welded into the windshield frame so that the stresses are dispersed over a wider area. The rear view mirror screws are not placed under any stress at all, they still only hold the mirror in place.



The rear mount uses four allen bolts to a plate with welded nuts inside the mount.



This bar will not only act as a chassis brace, but will also be used to secure the G-String bikini top instead of the PVC tube that comes with that top. The bar is also a "bolt in affair" (though stuff did need to be welded to the car to make it this way), allowing it to be easily removed. These pics show the bar in its unpainted state, but it is being sent out to be powdercoated for a nice finish. Once it's back in place, new SFI padding and a leather cover will be fitted to the rollbar again.
 
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#3 ·
Re: Blackbird Fabworx custom windshield bar

You'll have to take that up with Moti. Sorry.
 
#7 ·
Re: Blackbird Fabworx custom windshield bar

DO WANT!!!!!!!!!!

This will be perfect for my Bikini Top!! What Rollbar do you have David? Hope someone in CA has an NB harddog installed on an NA for measurments?
I have a HD HT with door bars. You need to know that this bar requires custom welding/fitting to be installed on the car (nuts welded to the windshield frame). I don't know if Moti will be able to release this as a true bolt-in kit that doesn't require at least SOME welding to install.
 
#8 ·
Re: Blackbird Fabworx custom windshield bar

Thanks for the great review, David!

Glad you guys like it, but as said, this isn't really a direct bolt on piece as some welding is required on the car and on the rollbar.
As such, there's a 50% chance that a good product like this one will get screwed up in the hands of an installer that isn't on par.
Not sure if I want to go there...

Some more detail shots:

Mounting plate at rollbar -


Mounting plate at windshield header -


Mounted w/ HT, the curve isn't an optical illusion, the tube was rolled into shape -


Pricing questions on PM please.

Moti
 
#29 ·
Re: Blackbird Fabworx custom windshield bar

As such, there's a 50% chance that a good product like this one will get screwed up in the hands of an installer that isn't on par.
ummm, how do you mess up installation? isnt it like 6 bolts total? and its not like you can install it backwards or wrong, youll know if your not doing it right. lol
 
#10 ·
maybe i can have the rollbar drop shipped to his office for welding, and then he can ship it back to me, LOL. Anyhow, its really a great piece!! I was considering doing something like this after if got my bikini top, but just have not have the free time. And then boom you come out with this! So not fair!! (shakes fist)
 
#11 ·
Do you have a rollbar?
If you haven't bought one yet, consider a BFW one.
I can have it made for you to already include the mounting pad in the center and go from there plus the bar with slotted holes at the windshield header side to have some slop taken into account.
Once the bolts are tightened down the slots won't matter as the plate will get sandwiched in.

Moti
 
#13 ·
Again, that is some impressive work, Moti. I enjoy the details and welds. It is obviously the result of a well-thought out design and very experienced fabrication. I am always leary of overhead tubing in a street car, but I know David uses harnesses. It would definitely add an extra level of protection to keep the windshield hoop from caving in if the car rolled over. I wonder if there is enough material in the header of a hardtop to add inserts at the center to attach it to the mounting plate you added? I know it would be a more permanent mounting solution for the hardtop for those who don't remove it...maybe it would put too much stress on the FRP the top is manufactured from.
 
#18 ·
This does not seem like a particularly 'sound' idea as KingFu has already alluded.

The A pillars in these cars are weak, as you'd expect any convertible to be. I can't imagine a single point tie in to the wet noodle that is the windshield frame will offer much in additional stiffness. I CAN imagine is flailing about the cabin in the rare but possible event of a rollover or stressing the windshield and causing fracturing.

While I am surrounded by ME's, I am not an engineer so my assumptions could be wrong.

-Zach
 
#19 ·
Thanks again to everyone's kind words.
The support from this community is awesome!

KFJ, I'll post another pic in a bit showing what you're talking about better.

Zach, with all things considered equal, the choice is between the windshield frame crashing down on you at the event of a rollover without any resistance or the windshield frame crashing down on you with resistance.
I don't see how the first choice is any better.

Hopefully Mr. woolery is up to post a pic at some point showing himself (and he's not a short guy) in the driver seat and how far the bar is from the driver's head.
You'll need to forget to buckle your harness to hit it, you're far more likely to hit the main hoop of the rollbar itself, but let's not open that debate, that horse has been beaten to death about a million times already.

The center bar was designed to reduce the windshield frame movement which as you can read from the review it works very well.

I'm not an engineer either, but have seen engineers making bad choices too.
Remember that amatuers built Noah's arc while engineers made the Titanic ;)...

Moti
 
#22 ·
This bar wasn't meant to provide significant rollover protection. Let me say that first. However, in a rollover, I don't think it'd flail about, either. If the purpose of this bar was rollover protection, I'd have gone about this in a totally different way. This isn't intended to turn a rollbar into a cage, just give a non caged street car with a rollbar the chassis stiffness that's similar to a cage but without the risks a cage presents when used in a street environment (bars too close to head).

It DOES work very well as a 7th member/chassis brace, tying the rear of the car to the front, and removes any residual vibration put into the windshield header by other chassis stiffeners and the existing rollbar. It basically compliments the chassis stiffening provided by the door bars.

As for spacing, this bar is far away from my head when sitting in the car...but not so far away that it can't be used as a convenient handle. :woolery:
 
#28 ·
It DOES work very well as a 7th member/chassis brace, tying the rear of the car to the front, and removes any residual vibration put into the windshield header by other chassis stiffeners and the existing rollbar. It basically compliments the chassis stiffening provided by the door bars.

As for spacing, this bar is far away from my head when sitting in the car...but not so far away that it can't be used as a convenient handle. :woolery:
Fair enough - I can see this dampening/eliminating vibrations within the window frame and with the door bars, it's ability (or inability) to add substantial structural stiffness is unimportant.

Anyway, the fabrication work looks well done - I wish I was on the west coast (as always).

-Zach
 
#24 ·
Couldn't you have a slightly curved bar that connects to the hardtop mounting points on the windshield frame and have this piece join in the middle to make a T shaped brace? That would make it easily removable.
Kinda like this.
 
#25 ·
It's already easily removeable. 2 screws, 6 bolts, and it drops out. In eyeballing it, I don't see any structural advantage to your design, though it does look like it'd weigh more.
 
#26 ·
It was just a thought. I know next to nothing about designing stuff. There's more metal so undoubtably it would weigh more.
I just thought that using the hardtop mounting points might help keep the corners of the a-pillar from collapsing in in the event of a roll.
 
#31 ·
Since the load will fall on the unsupported center of the bar and there's no direct support to the corners, either horizontal or vertical (as you would have in a cage), the T-bar design doesn't offer an advantage to the single center bar.

Moti
That's kinda what I figured would happen.
 
#38 ·
An X-bar will definitely improve the rigidity more than Dave's single bar but I would think there will be great risk of hitting your head on it.
 
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