Cannondale: Jekyll Ultimate HardTrail

The heart of this bike is its DYAD RT2 pull shock, which allows riders to toggle between 90mm and 150mm of travel on the fly. Developed with FOX, it is essentially two shocks housed within one body, each with its own air chamber, valving, and external rebound adjustment. There is a downside, however: The shock weighs 1.5 pounds, about a pound more than FOX's RP23 shock.

The Jekyll frame is also on the cutting edge. It's made from impact-resistant BallisTeccarbon, which Cannondale claims can absorb twice the impact as standard high-modulus carbon. At 6.6 pounds, it's not the lightest frame in this category, but it is stiff and reliable. Engineers also added oversize pivot axles with two rows of bearings, resulting in a stiff, easy-to-control bike. Despite its robust build, our 25.8-pound test bike felt more efficient while climbing than some lighter models in this test.

Flipping the handlebar-mounted switch changes the bike's travel and geometry to match the terrain: steep for climbing, laid-back for descending. In climbing mode, called Elevate, the Jekyll offers 90mm of travel with sag set at 20 percent. This provides a few inches of rear-wheel movement, perfect for absorbing rocks and roots while clawing uphill or on rolling terrain. In the Flow mode, travel increases to 150mm and sag drops to 30 percent, lowering the bottom bracket and slackening the head-tube angle. This setup lets you rip downhill as the suspension swallows rocks and drops. Quite a few bikes blur the lines between XC and trail riding, but the Jekyll offers a unique approach with a suspension that essentially makes it two bikes in one. It climbs well, speeds across rolling terrain and can still bomb downhill. That dual personality had testers lined up to take one more lap