It wasn't long ago when we as mountain bikers had to choose between a bike that rockets you to the top of a big climb, or a bike that mocks rock-gobbling descents for miles on end. Thanks to the modern trail bike we can have both of these things, although there aren't many that can match the level of trail-competence provided by Pivot's Mach 5. 5 Carbon. Slightly longer, slacker, and lower geometry matched with the DW-link's intuitive tracking abilities amount to an astonishingly capable rig for extended backcountry excursions and rowdy trails in steep and unforgiving terrain. This rig is a worthy choice for riders who require the ability to dance through low traction rollovers and ledges on the ascents and hammer down rock rolls and off-camber roots on the way down.The Mach 5. 5 Carbon retains the sought-after attributes of the DW-Link suspension platform, namely the ability to claw up the steepest, chunkiest climbs and soak up square-edge hits with unbelievable composure on the way down. Once you've reached the summit after a lengthy climb, 5. 5 inches of rear travel gobbles up loose rocks and smooths out successive square-edge hits when you're bombing downhill at high speeds. It's all party up front, with 6 inches of travel instilling confidence for rallying over rough sections littered with boulders, loose rocks, and speed-impeding root sections. This 20-millimeter disparity between front and rear travel gives you a bit more efficiency for pedaling, but with extra plushness up front for cleaning notoriously technical stretches of trail.Realizing the industry is ever-shifting, it makes perfect sense to see the Mach 5. 5 Carbon with a slacker, longer, and lower geometry for riders seeking unflappable composure at high speeds. The 66. 5-degree head tube angle offers stability on descents, without being overly slack or wandering excessively on sustained climbs with steep, punchy sections. Just a tick shorter in the front than the notoriously long and slack Fire...