I have an Xtracycle built lean and quick with the simple "hoodie" bag on the back. I use it to sometimes do my full 33 mile round trip ride to work. The Xtra is built from an aluminum hybrid and running 700c wheels with 35's or 38's. (check for tire fit if you are building one with 700c.)
A photo of the initial build without bags:
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The bicycle, the bicycle surely, should always be the vehicle of novelists and poets. Christopher Morley