Hey-sorry for the late reply. The rack is holding up great, (just about 2years) and I could have used just 2 bars. I think the key element was having solid mounting points for the feet. In my case, the steel rail/bracket running along the sides (meant for the Truxedo soft tonneau cover to roll over)provided ample support. Distributes the weight evenly, and off the actual truck bed panels. The cover can still be rolled over, although there are small gaps where the Thule feet clamp- no issues with keeping stuff dry though.