Boy, I thought I carry too much stuff. I carry nothing compared with you. I have panniers, and I usually bring just one, and often, the only thing in it is my ipad mini. I have a tool bag strapped to my saddle which has a tube, a multi-tool, a patch kit, and a (nearly useless) micro-pump. I keep a bottle of water on the bike, even in the cold months when I don't drink from it, because it's good for emergencies.