Many of you already do this, but I want to further extol the virtues of using more than one bike to commute. Yesterday I took this to work loaded with stuff and on the way home drop by the grocery store and bought about 25 lb worth of stuff, including a giant cabbage that probably weight five pounds.
You can imagine what the ride was like. The bike itself is already heavy, with rack, fenders, 32mm tires, and a large backpack.
Today I brought this:
Thin lines, 23mm tires, small backpack with very little in it. Nimble. Quick. Light. Complete opposite of yesterday.
My point is that having the option to ride more than one bike to work keeps things interesting for me and motivates me to get out in the morning. And this time of the year there's no restrictions on what bike you can and can't take