I am looking at the Sportworks Bob Ratchet and the Factory Bob. Both have relatively few but good reviews. The main criticism of the Bob Ratchet is that it takes up a lot of cross-bar real estate, presumably because the arm is mounted separately from the tray. The Factory Bob addresses this and has the two pieces integrated. But all the marketing material for the Factory Bob suggests that it is intended to be used with factory crossbars. My question is whether the Factory Bob will work with Yakima cross bars. Has anyone tried this? Had success?