@Webguy
You know I'm not sure on the capacity but I have some ideas. First of all, the crossbars are stout.. I stood in the middle on one foot and had zero deflection and I'm about 200lbs. Secondly, the numbers on other similar racks vary by are in the 300lb+ moving and 700lb+ static. The racks that are out there are full length like mine, not 3/4 like the one I'm talking about now so they used 1/4 aluminum. The full length rack has a cantilever that a shorter rack wouldn't so I don't think the extra thickness is necessary.. Weight wise, with aluminum, the difference is negligible. The cost for 1/4 is about 20% higher because of material cost and cut time .
What do you think the load requirements of your RTT are?
The picture shows my current bracket which was the result of some back and forth , the design is honed now and a little different but the basic idea is the same. The slots are adjustable because the gx roof measurement tapers from back to front. The new bracket has two slots vs one slot on my truck.
View attachment 1709677