Originally Posted by
zooma
I prefer a messenger bag for short distances when it isn't hot, but when it's hot I really like a trunk bag because panniers always have to be loaded on both sides for the weight distribution not to throw you off-balance.
Depends on the load and how balance-conscious you are. I commute year round, sometimes with one pannier, sometimes with both. When I use just one, it's full, especially if I stop for groceries on my way home. It doesn't have much of an impact.
--J