Bike Test: Pivot Mach 4
Has it really been six years since we’ve tested a Pivot Mach 4? Hey, it’s not our fault. Pivot springs so many innovative bikes on us?including the do-it-all Mach 5.7 trailbike, the long-travel Firebird, and the featherweight, carbon-framed Mach 429er?that it is easy to forget that the Pivot revolution started with the Mach 4. WHO IT IS MADE FOR?This isn’t an easy question to answer, because the Mach 4 is available in seven build kits, from the $6399 Shimano XTR to the $3999 Shimano XT/SLX build tested here. The further you move toward the high end, the more viable the Mach 4 is for serious cross-country racing, mostly because of the weight savings. Our Mach 4 was designed more for the trail rider, albeit the trail rider who likes to push the pace. 
WHAT IS IT MADE FROM?The Mach 4 relies on oversized, thin-walled, hydro-formed alluminum tubes; hollow, 3D forgings; and oversized pivots. The frame is available in six sizes, and the frame tubes are tuned for the specific sizes. The small isn’t harsh, and the extra large isn’t a noodle. Pivot uses a zero-stack headset system that allows the front of the frame to sit about 1/2-inch lower than normal. The zero stack differs from integrated headsets in that the bearings still ride inside a machined cup that is pressed into the frame. You get a PressFit 92-millimeter-wide bottom bracket, direct-mount front derailleur, and a dw-link rear suspension with a high-modulus carbon rocker. WHICH COMPONENTS STAND OUT?The Mach 4 XT/SLX component mix is special. It’s like Pivot’s engineers spec’ed a custom bike for a favorite client, but they are letting you ride it. How so? The non-matching Magura MT2 and MT4 (rear) brakes are something special that Magura does for Pivot. Pivot also specs non-matching Kenda Nevegal and Slant Six (rear) tires. The Mach 4 has a longer-travel Fox fork and wide handlebars with lock-on grips. It has a 2×10 drivetrain and a Shadow Plus rear derailleur. The shock is Kashima-coated. It comes with a WTB saddle, a wrapped chainstay and color-matched hardware. These aren’t choices designed to optimize profits; they are designed to optimize performance. 
Cornering: The longer-travel fork slackens the head tube angle, making this Mach 4 far more trail-rider-friendly than the steeper head tube angle you’d get using a 3.9-inch-travel fork. This, along with the sticky Nevegal tire, allows the rider to relax and flow the corners without stressing about obstacles (just hit them) or the trail surface (just roll it).
Climbing: While the dw-link rear suspension can handle out-of-the-saddle efforts, the Mach 4 will reward the rider for staying seated, selecting the Trail (or Climb) shock mode, and allowing the 26er-optimized 2×10 drivetrain to work its magic. Crewers were shocked to learn of the bike’s 28-pound weight. Not that 28 pounds is horrible; it’s just that the bike feels much lighter. The best technique for climbing on the Mach 4 is to maintain a light touch on the grips and to keep your weight forward and your torso low on steeper ascents. Otherwise, the bars will tend to scissor as the front end becomes light.
Descending: Maybe we should eliminate spec charts from our bike tests. Why? Numbers lie. We already told you the Mach 4 feels lighter than its actual weight, and now we are going to tell you that it has descending chops way beyond what you’d expect from a 3.9-inch-travel, 26-inch-wheeled “cross-country” bike. This bike is so much fun on downhill trails. Maybe in a side-by-side comparison the Mach 5.7 would provide a deeper feel on G-outs and the Mach 429 would roll smoother in craggy rock sections, but the Mach 4 delivers a feeling of complete control and confidence.
It may only have 3.9 inches of travel, but it is a great 3.9 inches. Braking: Pivot continues to deliver with this bike’s braking spec. The mix-and-match Magura MT2 and MT4 brakes are slightly heavier than the MT8 brakes because they undergo less machining to save weight. The additional material results in a stiffer caliper that provides increased braking power. You get plenty of stopping power up front and rear-wheel braking that allows for great traction control, even while moving through and over the rough stuff.
TRICKS, UPGRADES OR TIPS?This bike loves to be pumped along the trail (unweighting the bike on the face of bumps and weighting the bike on the backside) because the dw-link rear suspension has a firm mid-stroke. Whereas pumping will cause you to blow through the travel on other designs, the mid-stroke resistance makes pumping a blast on the Mach 4. You can also use this trait to slightly preload the suspension for hopping over obstacles. BUYING ADVICEThe Pivot Mach 4 doesn’t bring anything new to the table, and maybe that’s why we like it so much. Pivot has refined their initial offering, allowing riders to experience what a truly pedigreed mountain bike feels like. This bike is the real deal. It is a mountain bike, first and foremost. If you have already bought into larger-diameter wheels (29 or 27.5), carbon fiber frames or 5-plus inches of travel, we wouldn’t expect you to add the Mach 4 to your plan-to-buy list. This bike makes the most sense for a rider who wants to replace his five-year-old production bike. If you wanted to buy this bike five years ago but the price stopped you, well, friend, it’s time. 
_________________________ www.PivotCycles.com
