Pivot

Mach 5.5 Carbon Pro XT/XTR 1x Reynolds Mountain Bike - 2018

When the 2018 Pivot Mach 5.5 Carbon Pro XT/XTR 1x Reynolds Complete Mountain Bike was released we felt as if we'd been rekindled with a long lost friend — who happened to have spent the past 9-or-so-years at an Ivy League school studying suspension design, carbon fiber, and engineering, coming back into our lives reinvented and sophisticated. It was as if the old Mach 5 had been stretched and groomed into an all-capable trail-beast with geometry that's more capable than ever. In reality, it's more likely that the wizards — ahem, engineers, over at Pivot meticulously designed the Mach 5.5 with hints of its old flame, and a whole lot of new school geometry, elevated carbon fiber, and supple suspension that translates enduro badassery for all-mountain exploration. The result is a bike that we define as "damn capable," with slack and low geometry, deep suspension that soaks up the rootiest of tree lines, and hub spacing that lets us run beefier (but not too beefy) tires that track through loose berms and keep us composed with the trail goes buck wild.

The Mach 5.5 Carbon retains the sought-after benefits of the DW-Link suspension platform, namely the ability to claw up the steepest, chunkiest climbs and soak up square-edge hits on the descent. Once you've reached the summit after a grueling climb, 5.5 inches of rear travel gobbles up loose rocks and smooths out square-edges at high speeds. It's all party up front, with 6 inches of travel providing the confidence to rally across anything in sight, including sections usually reserved for longer-travel rigs. 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 sections of trail.

Seeing the industry is constantly evolving, it makes perfect sense to see the Mach 5.5 Carbon with a slacker, longer, and lower geometry for riders seeking a progressive trail bike that stays glued to the trail and retains stability at high speeds. The 66.5-degree head tube angle offers composure on high-speed 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 Firebird, the Mach 5.5 Carbon's long top tube gives you ample cockpit room, which is especially welcome if you have a longer reach. This longer front end is complemented with snappy-short 16.93-inch chainstays. Shorter chainstays provide greater maneuverability for cleaning tight corners and uphill sections, as well as lifting the front up and over trail obstacles.

A few key details make the Mach 5.5 Carbon a truly stand-out trail bike. Delving into its carbon frame construction, Pivot employs their proprietary hollow core internal molding process with an optimized lay-up of high-modulus carbon for the lightest weight possible. This method produces a feathery-light frame (claimed as low as 5.7lb) that approaches Mach 429 SL Carbon territory, but with strength and stiffness similar to the enduro-bred Mach 6. In the rear triangle, both the seat and chainstays clear tires of 2.6 inches, which is a nice benefit for riders seeking the added bump compliance and cornering grip of high volume trail tires.

A major role player that helps make the Mach 5.5 Carbon Pro XT/XTR 1x with Reynolds Wheels a truly stand-out trail bike is, well — the Reynolds wheels. The upgraded Reynolds Carbon Wheels, which are renowned for their stiffness, strength, and quick acceleration, elevate the bike in performance, while minimizing the weight, for power that doesn't deflect when you charge into the chunder, and tracks through loose berms with deliberate control. This Reynolds Carbon Wheelset features a 36-millimeter width for optimal support of the wider 2.6-inch trail tires provided on this build, as well as Industry Nine hubs with a responsive 3-degree engagement for powering up and over trail obstacles. This is topped off with cherry-picked Shimano XT and XTR-level components, offering you clean, crisp shifting, and exceptional brake modulation to add more precision to the ride.