BEST FOR: Fast racing on rough terrain. THE TEST: We were amazed at how well this stripped-down shoe—at 7.4 ounces, one of the lightest in our test—handled treacherous singletrack. La Sportiva’s designers gave the Vertical K a liberal dose of its ultralight, wavy Frixion rubber, made to deform around rocks and roots. Then they cut away unnecessary material underfoot, shaving more ounces and keeping the outsole flexible and responsive. Our only complaint: the upper material hides several loops of laces, keeping out dirt and debris but making the Vertical K a challenge to loosen after long runs. THE VERDICT: La Sportiva’s best trail shoe yet takes an innovative design and improves on it. 7.4 oz
Simple, single-material uppers, like those on the La Sportiva and the Gear of the Year-winning Montrail, are on the rise. Eliminating layers of fabric on the upper makes shoes lighter and more comfortable.