The spacing on your cross bars is dependent on the model and size of tent you have.  See the below chart: High Country 55”:  32” – 36” High Country 63”:  36” – 42” All other tents (approx. 85” long):  42” – 48” In some cases, especially with the High Country 80” that could hold 4 or more people, it’s recommended to use a 3rd bar for better weight distribution on your vehicles roof.  Always check you vehicles owner’s manual to see what your static weight rating is.