Looking to purchase one this week for an upcoming road trip - was going to 21 but worried about length. Have a side shot by chance?
I use a 21 on top. Unloaded, it wiggles on the stock crossbars, but I've since added AO rails and 4 Yakima Corebars as crossbars. There is no worrisome load limit with 4 Corebars. Yakima says I could put 300 lbs up there, but I'm comfortable with a little more.
Gramaviti is a great rack solution, but I have access to Yakima stuff at an advantageous cost.