My commuter usually tows a Burley Piccolo trailer. The trailer itself is just under 20-lbs., but it requires a heavy-duty Moose rack that adds another 3 pounds. My panniers are stuffed full with a lunch, coffee thermos, change of cloths/shoes, two bike locks (one for the trailer), a few tools and spare tubes, and my work computer--probably another 15 pounds at least. I estimate the bike itself weights around 26 pounds.

So, my whopping total is about 64 pounds! And that's when I'm not hauling my 55-pound daughter, who sometimes pedals.