Single or Dual Roll Bars

[joyridin']

Originally Posted by AL427SBF

FYI, U.S. law requires that the windshield frame on convertibles be able to support the weight of the car - why is that?

A quick look at sport convertibles (like Miata's, BMW Z4/Z6, Porsche Boxer, Cooper Mini's etc.) shows most have factory installed dual roll bars - why is that?

There's a track day event and you decide to go, no roll bar so you can't play - why is that?

Some tracks require instructor seat time 1st, no passenger roll bar, go home - why is that?

According to some, roll bars have nothing to do with safety (or increasing a level of safety), but I can't connect the dots as to why so they need to elaborate a little more. Why are these dual roll bars so popular on many sports cars, a factory installed item, and required for recreational track days?

I think you might need to do some research. Convertibles are exempt from this law.

Standard No. 216; Roof crush resistance; Applicable unless a vehicle is certified to 571.216a. - Federal Motor Carrier Safety Administration
Standard No. 216a; Roof crush resistance; Upgraded standard. - Federal Motor Carrier Safety Administration

Also, Europe really has no standard either. Certain manufacturers, like the ones you listed, have taken it upon themselves to create a rollbar type of safety device, but they are still not int he same league as a true rollbar. Most were tested by turning the car upside down and letting it rest on these supports. If you were moving down the road at 60 mph and the car flipped, all bets are off.

The fact is simple: If you are in a car without a roof or a full cage and it rolls over, you will probably die.