If your summer bike tour is going to take you through different climates then the UltraLite is a good choice. With a 59? shoulder girth this efficient bag is good to 20?. The full down collar helps to seal in heat around your neck without adding excess bulk, and 16 oz. of high lofting down pumps this bag to 5?. The total weight of this very compressible package is only 1 lb. 13 oz.