I'm planning on doing a 2000k ride next month and am deciding on purchasing options for luggage. Since I don't have much extra money for proper gear (tailbag, tankbag, etc) I was considering either using my expedition camping style backpack (about 60liters size) or strapping a dufflebag onto the passenger seat. I would think fatigue would the biggest concern with the pack loaded, but what about aerodynamics? (The trip is mostly flat prairie land with LOTS of wind). Any advice or similar experiences that could help me out would be greatly appreciated. :cheers