I second what others have said about sweaty backs. OTOH, I don’t like the additional weight of rack + pannier. However, I’m fortunate to have access to a shower/changing room at work, and enough space in my cube to preposition clothes. In the summer, this allows me to ride in with nothing more than a small handlebar bag to hold my wallet, lunch and underwear. In the winter, when I often have to add/shed layers, I use a backpack to carry my extra gear.
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