Good point. That is kind of my feeling now, I weigh over 260, and am reasonably fit (~180 miles a week). So I don't worry about people so much where I go, but I have yet to meet a dog that cares how big you are. The bite still hurts. For this reason, I'm thinking of getting my hands on some mace.
However, if I mount it on my bike, that is one more thing I have to take off my bike each time I get to work. The other things include, panniers, headlight, headlight battery, 2 rear lights, cycle computer, water bottles, and then I can lock it up. It is a process.