The main hoop (behind the driver) must be the full width of the cockpit for all cars. It must be one continuous length of tubing with smooth bends and no evidence of crimping or wall failure. The main hoop must maintain a single plane.

A. On all closed cars, the main hoop must be as close as possible to the roof and “B” pillars.

B. On open cars retaining the windshield frame, the main hoop must be full height for the entire width of the hoop. The top of the main hoop must be at least 2 inches above the driver’s helmet.

C. Open cars without the windshield frame may use an asymmetric main hoop. The main hoop must be full width to the passenger side of the car. On the passenger side of the car, the hoop must be at least as high as the top of the rear corner of the door. The main hoop must be high enough that a straight line drawn from the top of the main hoop to the top of the front hoop would pass over the driver’s helmet and steering wheel when the driver is seated in the normal driving position. Additionally, the top of the main hoop must be at least 2 inches above the driver’s helmet.