On a couple bikes I have Carradice saddle bags and no rack, so if I need to carry more, I use a large fanny pack. Between the Carradice Zip Roll and large fanny pack, I can carry extra undershirt, dress shirt, lunch, base layer, and have room to stick my sweater in the fanny pack on the ride home when it's warmer. If I ride the Miyata with the Nelson bag, I can carry just about everything in there. If I need to pack for rain, my jacket rolls up really small and will fit wherever I stuff it.