panniers for my commuting clothes and heavy stuff...

except i also carry a packpack with my basic papers and stuff in it. i have a special Deuter backpack with a mesh back so there is lots of airflow so the "sweaty back" is minimized.

i often think i should leave the backpack at home, but i just like having all my "stuff" with me.

occaisonally when i ride one of my other bikes to the office i carry all my gear in the backpack as the full suspension and road bike don't have racks. it works for occaisonal riding, but i don't like so much weight on the back and wouldn't do it every day.