The last big breakthrough in mountain biking was the creation of 29-inch wheels – bikes equipped with them, while slow and unwieldy, could pancake everything in their path, and made newer riders confident enough to saddle up and take on steep, rocky downhills. Now there's a new sweet spot: the 27.5-inch wheel. These have plenty of leverage over roots and rocks, but are lighter and have a shorter wheelbase than 29-ers. This means riders can be more playful with them, and so can mountain-bike manufacturers, who are changing geometry to accommodate nimbler, easier training. We pedaled hard to find the best of this new breed.
Scott Genius 740
Many mountain bikes foster a loose, laid-back vibe. The 29.7-pound aluminum Scott Genius 740, however, reflects its all-business Euro engineering. A handlebar-mounted switch lets you lock the suspension fully rigid, so all momentum-robbing climbing traction is eliminated. Point the bike down the mountain and it darts around and aims beyond apexes. While not as lively as some other 27.5-ers here, this rig rewards going full-on like no other. A must if you crave speed. [$3,000; scott-sports.com]
RELATED: Best New Mountain Bike Accessories to Upgrade Your Setup