I guess I am confused. I am figuring that a knee brace is different from the gussets required. I have a complete continuous front hoop right behind my firewall with an "X" welded in the center of the same dia tubing as my cage, which I guess would take place of the knee brace. My shoulder bar also has the required gussets made of .125 X 4" wide welded shoulder bar to my uprights as required by SCTA 3.B.1 "Roll Cage".
FYI....to me, I would be concerned that the "knee brace" would not be tough enough to keep the tubing uprights straight in case of a side impact roll over especially if they have additional bends in them, which would make them weaker in compression. That is why I have the "X" welded in my front hoop (right behind the firewall) plus another right behind my seat. For more strength, I have another "angeled" upright (V-Shape with the bottom of the "V" welded to a plate that bolts to my frame) on the passenger side of my car and connects to the back uprights (that go over my head) and the other leg is welded on to the shoulder bar where it intersects with the with my main front "overhead" hoop. What concerns me the most is that with the roll cage and seating being to the extreme left on a street roadster, there is very little area for additional uprights to the drivers side of the car, because of the positioning of the roll cage, but alot of room to the passenger side of the car for additional roll cage support, which I have used for additonal support. I have raced for many years in both drag racing and circle track, and I place a high value on side and front impact protection to keep my cages from caving in or moving under extreme circumstances.