Roll Bar Connected to Windsheild
#22
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It (roll bar) wasn't designed to keep the windshield in mint condition if you had a rollover.
Don't forget something, even a terrible rollover with a roll bar still has a solid structure supporting the car. The point isn't to keep the windscreen from crushing, its to keep YOU from crushing by supporting the mid/rear point of the car.
Even if the windscreen frame still collapsed during the crash I don't see the extra added bars doing any harm, but speculate it might add just a tiny bit of extra structure. However with that said I'm not an engineer so my speculation is worth basically nothing.
Don't forget something, even a terrible rollover with a roll bar still has a solid structure supporting the car. The point isn't to keep the windscreen from crushing, its to keep YOU from crushing by supporting the mid/rear point of the car.
Even if the windscreen frame still collapsed during the crash I don't see the extra added bars doing any harm, but speculate it might add just a tiny bit of extra structure. However with that said I'm not an engineer so my speculation is worth basically nothing.
#24
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Location: Boston / '90 Mariner Blue
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I've had this discussion with a friend of mine, who was looking for increased rigidity & safety while trying to avoid the full cage (he really like my bolt-in front cage section), and, while looking into center roofline bars, several people told him that the windshield WILL fold in during a rollover, most likely taking the roofline bars along with it.
Now, if you had installed bars along the windshield, running down into the floorboards, THAT WOULD be a slight improvement, which WILL keep the roofline bars from collapsing, but, the corners of the windshield will still fold in in a rollover, hurting the driver.
Now, if you had installed bars along the windshield, running down into the floorboards, THAT WOULD be a slight improvement, which WILL keep the roofline bars from collapsing, but, the corners of the windshield will still fold in in a rollover, hurting the driver.
#26
Do not want.
One more thing to hit your head on in a street car, for minimal benefit, and a track car is better off with a full cage.
Since it is a boxed off section it may hold up better, as the longitudinal bars would technically be in compression, and not see a bending moment until the A-pillars buckle. In reality buckling cannot be assumed to happen uniformly, and the front welds would like not hold.
Even if it stays together, when the windshield frame is compromised the bars may actually push back on the roll bar, making it more likely that the rear mounting points would puncture through the chassis.
#27
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Location: Boston / '90 Mariner Blue
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For street driving, you must have dual durometer padding on your rollbars. Not really necessary behind the seat, but, crucial for any metal bar that your noggin' might come in contact with.
#29
If you dray a line from the front cross member to the top of the bar you get the idea. Every flipped Miata I've seen has looked exactly like that. No one is expecting the windshield frame to do anything.
EDIT: Tall people may not fare so well...
#30
Most rollbars are designed to preserve your head by supporting the weight on the nose of the car, and the rollbar hoop.
If you dray a line from the front cross member to the top of the bar you get the idea. Every flipped Miata I've seen has looked exactly like that. No one is expecting the windshield frame to do anything.
EDIT: Tall people may not fare so well...
If you dray a line from the front cross member to the top of the bar you get the idea. Every flipped Miata I've seen has looked exactly like that. No one is expecting the windshield frame to do anything.
EDIT: Tall people may not fare so well...
#31
Roll bars protect your spine from compression, ergo they carry half the weight of the car instead of your weak, never-seen-a-gym, puny back.
You can fix scrapes, and live through several concussions and still be fully functional. Spinal injuries usually leave folks in wheelchairs.
#32
My question is: How likely are you to get sliced up by that windsheild? Contact with the ground is unlikely sure, but that windsheild is pointed right at your face. If you plant that sucker right into a tree stup it looks pretty easy to slide it right into your face or neck and off it goes. Yeesh.
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