Rollcages (for Road Racing)


  • Whats the difference between a bolt-in and custom rollcage?
  • Where do I buy a bolt-in rollcage?
  • Where can I get blueprints or designs for a custom rollcage?
  • Can I use a 4 pt rollbar for racing?
  • What about a 12 pt cage?
  • Whats the difference between ERW and DOM and chromoly steel tubing?
  • How much stiffer does a rollcage make the car feel?
  • Can I use pipe insulation foam or pool toys as rollcage padding?
  • What does "Nascar doorbars" mean?
  • Is this rollcage legal?
  • Can I drive my car on the street with a rollcage?



    Whats the difference between a bolt-in and custom rollcage?
    You can buy a bolt-in rollcage that is prefabricated for your vehicle and will literally bolt in to your chassis in parts and secure together by bolts (go figure). Bolt in kits are usually made to accomodate Showroom Stock cars and can be installed without removing most of your interior. A custom rollcage is welded directly to your chassis and can be fit more closely to the chassis allowing extra room. Installing a custom rollcage requires skilled knowledge of welding and special steel tube bending equipment. Labor can be expensive when hiring an experienced professional or shop, on top of material cost. Cost of custom cages varies as labor rates vary, but typically from $1500-3000. The benefit of a custom cage allows building a more effective and perhaps stiffer cage tailored to your personal requirements and welding the cage to the chassis is preferred to bolt-in for its inherent greater bond strength. (a poorly designed and built cage will obviously lead to bad results, which is why an experienced professional is needed - its not just farm equipment youre putting together, its a safety device.) Weld-in kits like bolt-in kits are also available and you are free to customize your bolt-in cage with any legal modifications.

    Where do I buy a bolt-in rollcage?
    There are two manufacturers of bolt-in kits that are popular, Autopower and Kirk Racing. I/O Port Racing has a good FAQ on Autopower cages. Both brands provide the basic layout of a legal rollcage and also have DIY weld-in options. They differ a bit in actual design, but to my knowledge offer little difference in function.

    Where can I get blueprints or designs for a custom rollcage?
    There are minimum requirements for building a rollcage for each class in the GCR. IT has different requirements than GT (Grand Touring) or Touring. The GCR should have some guidelines including defining tube thickness, but apart from that, there are no specific blueprints available for cars that I know of. Again, it is important to have an experienced builder for this.

    Can I use a 4 pt rollbar for racing?
    No. A 4 pt rollbar is only a main hoop and 2 rear supports. Minimum design for road racing must have forward supports from the main hoop following the roofline and down the A pillar to the floor, with a horizontal doorbar connecting the two vertical bars to protect the driver from side impact. A rollbar would be fine for non competitive use.

    What about a 12 pt cage?
    Improved Touring rules only allow maximum 8 pt cage. Different classes and organizations have different rules for the level of preparation of the cars. Minimizing or specifying the number of attachments points limits the amount of added structural reinforcement (as a chassis performance modification) while providing adequate level of safety for the specific class or type of car.

    For example, a rally car is raced on courses with extra hazards like tree trunks, stone walls and rolling down cliffs that require a different level of protection. And need to protect two passengers also. Although I have no specific knowledge of what is required for a proper rally cage, I can firmly say it would be different.

    Whats the difference between ERW and DOM and chromoly steel tubing?
    From I/O Port website: ERW stands for Electric Resistance Welded. This is a mild steel tubing that started out as a flat sheet of steel, formed into tubing and welded. DOM stands for Drawn Over Mandrel and it is actually ERW tubing that has gone through a second process that shapes and smooths the tubing so that the walls are more uniform. This in turn makes the tubing stronger than the original tubing. Chrome-Moly is an alloy of steel which incorporates both Chromium and Molybdenum in the process. Please don't confuse Chrome-Moly with Chrome finish. All our roll bars are painted Black.

    New SCCA rule change requires all newly registered cages to be made of DOM effective 2003.

    How much stiffer does a rollcage make the car feel?
    Chassis stiffening is a side effect of a rollcage, not the primary function at the club racing level. However, I imagine it stiffens a car a lot. I personally couldnt tell and dont care at this point.

    Can I use pipe insulation foam or pool toys as rollcage padding?
    No. Rollcage padding is special impact absorbing material and should be fire retardant. The typical foam padding is also usually eccentrically bored to allow extra thickness in the right direction. Padding should be installed on every bar in all possible locations of body contact. Rubber strips such as Ensolite is also used instead of Ethofoam, but must be 0.5" min thickness.

    There also exist a more denser type of rollbar padding called BSCI that is supposedly more effective for high speed impact than the "insolation" type of padding. After doing my own reading, I would recommend using this type of padding instead. You can read for yourself here. (link)

    What does "Nascar doorbars" mean?
    A Nascar doorbar is a design where the drivers side door beam of the rollcage is extended into the door to allow extra space between the doorbar and the driver. Minimal design would be two (nearly) horizontal doorbars with connecting trusses. This design also requires gutting of the door. Current rules state in IT that only the drivers side is allowed for this. (Not to be confused with the new Touring rule which allos it on both sides.)

    Is this rollcage legal?
    Buy a rulebook and get your cage checked out by a regional tech.

    Can I drive my car on the street with a rollcage?
    There is no law that I am aware of specifically prohibiting a full rollcage on the street and I never had a problem personally with police. However, a rollcage should only be needed for competitive racing to be installed in purpose built race cars. Which means there's no reason to have a rollcage without actually racing. (Its a lot of dead weight to be carrying...) I have personally used my racecar at a somewhat limited level on the street and had no legal problems, but I understood the extra risk I was taking with being surrounded by 2" metal bars inches from my head, without a helmet but always strapped into my harness. I dont see any issue with a rollbar installed on a street car as there is no forward metal.










    The purpose of this FAQ is to provide a centralized source of information to common questions frequently asked that provides a comprehensive answer that may not be given for each time a question is answered. I just wanted a place to brain dump my knowledge. All information in this FAQ is a product of my own thoughts and shall be regarded as my own opinion, unless otherwise noted. Take it for what its worth. I do not pretend to be an authority and am open for correction and input.