Well, so far I've determined that the under-seat storage can fit two 20-oz MSR fuel bottles, with enough space left for a small cable lock or rotor lock. I need to figure out a way to keep the fuel bottles from moving around, but that gives me a little wiggle room for touring on this machine. Unfortunately the 30-oz bottles do not fit. It looks like it could fit two longwise, but they just don't clear the frame rails. It's too tight.