The best windshells walk a fine line between protection and breathability, not to mention durability, weight, and packability. The Helium handles that tightrope with aplomb, prompting one tester to name it “the only shell I need on most days.” Credit the 30-denier Pertex Diamond Fuse fabric, which weaves interlocking, diamond-shape nylon filaments together for added strength and water resistance. It shed continuous rain in Montana’s Bitterroot National Forest for 90 minutes, kept us warm into the 30s while bombing downhill on a mountain bike, and provided impressive durability for a shell this light. “I climbed Mt. Moran in this, which had me scraping along the rough rocks of the wall,” says a Wyoming tester. “It came off the mountain without a scratch.” The Helium breathed well enough for trail running in blustery conditions and uphill cycling in the 40s. (The women’s version, which places a more breathable stretch-woven polyester/spandex fabric on the lower half, even more so.)
m’s S-XXL, w’s XS-XL