Best For: Endurance racers.
The Test: As the name suggests, this four-inch cross-country carbon racer is a highly tuned instrument for dissecting the competition. It was nearly the lightest mountain bike we tested, which left everyone gushing about “explosive” starts and “effortless” acceleration. But for a race bike, the Scalpel was surprisingly supple. The Lefty 29er Carbon XLR fork quieted trail chatter, and we loved the convenient bar-mount lockout lever and unflinching stiffness it delivered. The rear suspension got a little squirrelly on anything beyond choppy trails, but not unusually so for such a lightweight ride.
The Verdict: Do the Breck Epic, sign up for a 12-hour race, or simply take it out and demoralize your buddies by dropping them repeatedly. 23.3 lbs