Roll Bar Basics

Turning a sports car on its lid is not something any enthusiast expects to happen, but you should be prepared for the worst. Damaging your ego or your pride-and-joy is one thing, but more serious is the potential for personal injury. Adding to the danger is the fact that many sports cars are stuck with 1960s technology when it comes to safety considerations. Modern production cars have crumple zones, airbags, rollover protection and built-in side beams to prevent intrusion.


Traditional European sports cars often have no rollover protection, or roll bars that are more cosmetic than structural. Not only that, many aftermarket roll bars are not made to racing standards. Although they are better than nothing, the effectiveness of any bar is dependent on many factors including design, wall thickness, tubing type, diameter and the method of attaching it to the frame. Many bars would fail if "tested" in an actual accident, while others not only make the cars safer, but handle better as well!

Roll Play
The first consideration when installing or upgrading a roll bar is usage. If track events are planned, the design part may be done for you. Simply follow the regulations provided by racing clubs. Autocrossing involves relatively low speeds and events seldom require rollover protection. However, high-speed solo events that take place at racetracks usually require rollover protection. Wheel-to-wheel track or drag racing, no matter how well regulated, is dangerous business and roll bars or cages will usually be required. Even if they aren't, you don't want to risk your neck in an unsafe car.


To get started, ask any clubs or tracks that you plan to compete with for a copy of their regulations. Follow them as gospel, but if you decide to improve on them check to make sure you are within the regulations. Extending the roll cage through firewalls may stiffen the chassis, but is illegal in some clubs or classes. If you are not going to race, it still pays to get copies of regulations as they are written by organizers more knowledgeable about high-speed accidents than you are.

Cage or Bar?
First decide whether you need a roll bar, cage or a partial cage. If you do not intend to run track events other than autocrossing, then a simple bar may suffice. With a street-driven car you may have to design a bar that will fit under a top or satisfy some other practical consideration. A partial cage may include a roll bar combined with side-impact bars and/or a cowl bar that fits under the dash. This maintains the original lines, but beefs up both protection and chassis rigidity (albeit at the expense of ease of entry).