You can resist giving up your favorite pair of bib shorts for a few weeks, or maybe a month or two of fall, but eventually, your legs are going to need some more protection. If you want a one-piece solution to keeping your lower half warm during cold-weather cycling, Castelli’s Nanoflex Donna Tights represent a sleek, highly functional choice. They have a built-in KISS Air Chamois so you won’t need to deal with layering, and are constructed with Castelli’s Nano Flex fabric, which wicks moisture quickly away from your skin to manage body temperature. Water beads up and rolls off immediately when it hits Nano Flex, so you won’t need a shell with these tights if you’re heading out on a day with threatening skies, and Castelli used as little seaming as possible to eliminate areas where water could get into the tights. Castelli shows its continuous attention to the small details that contribute to a piece of clothing’s functionality as well, using Giro3 ankle grippers to create seamless, sealed integration with your shoe covers, and including ankle zippers that make it easy to put the tights on or take them off. As a final touch, reflective accents on both the zippers and the sides of the legs help enhance your visibility as you try to pedal home before those early winter sunsets.