I use a backpack for my 22 mile commute. However, I don't haul much in the backpack so it's very light, about 5 lbs. I've got a locker at work that I stock with clean work clothes and supplies so usually all I carry in my backpack are some basic tools, pump, spare tubes, spare tire, batteries, phone, wallet and keys. I try very hard to keep from collecting, and hauling, non-essential things/weight in my backpack.