Originally Posted by
Lava
That seems like a nice option if you have a rack. It's always nicer to not have the load on your back if you can manage it.
I don't have a rack on my bikes, and use an
Ortlieb Messenger Bag as my commuting bag. Used to have the smaller Velocity model, but it was often too small for everything I needed for work: a change of clothes, shoes, lunch, laptop, etc...The Messenger Bag size is just fine, though.
Just to put it out there...Axiom makes a rear rack that will fit on bikes without eyelets, goes on the quick release skewer/axle. Years ago I used to commute with a backpack. These days I'm all about a rear rack, would never give them up. Just sayin'. I love racks on commuter/grocery getters!