Hey guys, I'm new to te bike packing/ touring scene and I am buying myself a new steel frame to build for the tour across America I will be venturing on next year. I want to put some avid bb7 brakes on the bike and I want to know what size rotors to get. The frame I will be building on Will either be a tout terrain grande route from Peter white cycles or a Gunnar grande disc. I'm thinking 160 on the front and 140 on the rear? What size rotors do you guys use in your disc touring rigs?