The thing that's nice about the bars is the spacing is perfect for supporting your keyboard, they're lightweight, install in just a few seconds and they don't take up a lot of room in the van. I tested them for weight capacity by placing a sheet of plywood on the bars, then sat on the plywood. I weighed just over 185 at the time.
Here's a photo of the cart fully loaded, and I still have more space available at the bottom level.
On the cart's bottom level is the Bose L1 Compact, mic and cables bag, and custom console bag. On the top is the keyboard, two-tier X-Stand, fan, extension tubes for the Bose L1 Compact and my Quic Lock stool is attached to the cart handle and lips over the legs of the X-stand to anchor everything in place.
All the best,
Gary