This is my wife's packing method. She pulls away from me when I'm going 40+ mph on downhills without any problems. She can also shift and trim very well on her 9 speed triple
I have 3 touring bikes: Surly LHT, Cannondale T2, and a Bianchi Volpe. The Volpe is my favorite. All our touring bikes, 6 including our daughter's bike, are equipped with 22/32/44 chain rings and an 11-34 cassette.
My Ortlieb Rackpack holds pillow (orange), tent (blue), Thermarest pad (orange), and sleeping bag (yellow). The tent and sleeping bag are in water proof compression sacks. The loaded rackpack weighs 10 lbs., including tent poles, tent stakes, and ground cloth.
Tent compared to water bottle for scale.