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Pivot Cycles has been on a bit of a tear. The company’s Mach 429 SL, Mach 429 Trail, Switchblade, and Firebird have all been well received by our testers, resulting in numerous Editors’ Choice awards.
But the company has had a conspicuous hole in its line: a mid-travel 27.5 trail bike. This hole had been the domain of Pivot’s first carbon full suspension bike, the Mach 5.7. First launched in 2011, the 5.7 was a 140mm bike that began life as a 26-inch-wheel bike, though at the end Pivot was shoehorning in bigger wheels and selling it as a 27.5-inch-wheel bike.
Today, Pivot has launched the Mach 5.5 Carbon, a dedicated 27.5-inch wheel platform with 140mm rear travel designed to be “a real mountain biker’s mountain bike,” say company representatives. I traveled to Moab, Utah to get the first look and my first rides on Pivot’s latest.
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Meet the Mach 5.5 Carbon
Pivot’s latest bike is made with a carbon frame (an aluminum version may be offered in the future) based around 27.5-inch wheels with 140mm of rear travel; complete bikes are equipped with a 160mm Fox 36 fork. The frame has clearance for 2.6-inch wide tires (the Mach 5.5 is not designed for plus widths or 29-inch wheels) and has the expected low/long/slack geometry.
I asked Pivot’s founder and head designer Chris Cocalis to describe the rider the Mach 5.5 is designed for. His response: “Pretty much any trail rider...Between the frame weight and the overall features—and even the combination of the rim width and tire width—it's a real mountain biker’s mountain bike.”
If you’re shopping for a trail bike today, you’re inevitably faced with the 29 versus 27.5-inch question. In addition to the 140mm rear/160 front Mach 5.5 here, Pivot also offers the 135mm rear, 150mm front Switchblade. The intended use of the two bikes overlaps, and even geometry is quite similar. So to, hopefully, help potential buyers identify which wheel size would better suit their needs, I asked Cocalis to provide his take on the differences between 29 and 27.5-inch wheeled bikes.
“Obviously a 29er wheel rolls over stuff really nice,” Cocalis said, “But with that you lose some agility and the ability to pop off stuff in the same way, and the flick-ability of the bike. And when you get to 27.5 wheels, obviously you’re going to give up just little bit of that rollover, but the riding experience, for me anyway, it’s more dynamic. I can jump the bike easier, I just feel like, as a rider, I’m in more control of what the bike’s doing. ”
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The Frame
The 5.5 Carbon’s frame shares much of its design and features with other current Pivot frames.
Like all Pivot suspension frames, the DW-Link design is employed on the 5.5 Carbon. Every pivot on the Pivot’s short dual links uses a sealed cartridge bearing. One new feature debuting on the 5.5 is a flexible rubberized cover atop the lower link to shield it from gunk.
Pivot is claiming the 5.5’s frame weighs between 5.2 to 5.5 pounds with shock (a frame sample weighed at the launch indicates these claims are believable). This is quite light for a 140mm frame intended for aggressive trail riding, and is about a pound lighter than Pivot’s 155mm travel Mach 6 Carbon frame, despite the 5.5 achieving similar frame stiffness.
Cocalis stated that the 5.5 employs more high-modulus carbon than any previous Pivot frame, which allows designers to lower weight while maintaining stiffness. Of course, the material also adds to the frame’s price: jsut the 5.5’s frame sells for $3,099, $100 more than the Mach 6 frame.
Five sizes are offered—XS through XL—and frame geometry is in line with other modern trail bikes designed for aggressive riding: longer front centers; lower bottom bracket (340mm); 430mm chainstays; 66.5-degree head tube angle and 73.5-degree seat tube angle.
Top tubes are low for generous standover clearance (686mm for the XS size; 711mm for the XL), and seat tube lengths—356mm (XS) to 495mm (XL)—were chosen in anticipation of longer-drop dropper posts. The combination of standover and seat tube lengths means most riders can comfortably ride a few different frame sizes, allowing them to pick their size based on front-center length (longer front center, more stable; shorter front center, more maneuverable).
Housing and hoses run internally through the frame. Pivot’s clamping ports allow the hose and housing to be pulled taut and locked down, preventing the scourge of rattle and slap. The 5.5 is also Shimano Di2-ready with compatible port covers and a battery door and holder just in front of the bottom bracket.
The covered port in the non-drive chainstay near the dropout and the pad under the top tube near the forward shock eyelet are provisions for Fox Live, a forthcoming electronic system for automatically controlling fork and shock damping. Pivot and Fox representatives were unwilling to provide on-the-record details about Fox Live’s technology, or when the system might be publicly available. However, the fact that the 5.5 Carbon is provisioned for Fox Live seems to indicate that the launch on the foreseeable horizon.
The 5.5 is compatible with front derailleurs (remember those?), and a removable e-type adapter is included with every frame. For the pack-averse, the 5.5 fits a large bottle in the main triangle (with the stock shock) and has a mount under the BB for a second water bottle or tool carrier.
Soft rubber guards in appropriate places quiet chain slap and provide rock-strike protection. Boost 148mm spacing is employed in the rear (complete bikes have Boost 110mm forks), while the press-fit 92 standard (with ISCG ’05 tabs) is used at the BB shell. Two colors are offered: a semi-gloss red frame with black graphics and black frame with blue graphics.
Build Options
The 5.5 Carbon will be offered in nine complete builds which start at $4,899 and top out at $10,199. All complete bikes use the same frame and are equipped with 2018 160mm travel Fox 36 forks and Float DPS shocks.
The highest end Team builds come with a Pivot-exclusive Reynolds carbon wheelset with 36mm internal width and Industry Nine hubs (this wheelset is an optional upgrade to Pro builds). Cocalis said the wheelset’s final dimension was arrived at after testing many different widths before arriving at the one that he felt best suited the bike’s intended purpose, and the tires he recommends for the bike.
Those tires, on complete builds, are 2.6-inch Maxxis Minon DHF front, and Maxxis Rekon rear, in Maxxis’s Wide Trail (WT) casing, which is specifically designed for wider rims.
Lower priced builds use a 2018 DT-Swiss M1700 wheelset with 35mm internal width.
All models use Pivot’s Phoenix Team Enduro/Trail stem with 35mm bar clamp, Phoenix 35mm handlebar for WTB’s PadLoc grip system (carbon on Pro and Team models, aluminum on Race models), and Pivot’s 32.5mm-diameter PadLoc grips which boast the “softest durometer of any grip on the market.”
Fox’s highly adjustable Float X2 Climb Switch piggyback shock is a $399 upgrade for any build.
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The Ride
The crew at Pivot held the 5.5 Carbon’s launch in Moab, Utah. On the ride plan were some of the more technically demanding trails in the area, including Gold Bar Rim, Portal, Hymasa, and Captain Ahab. I rode the $8,299 Team XTR 1x model, which weighs 27 pounds, 15 ounces on my scale.
My overarching impression of the bike is that it is excellently balanced. The terrain we rode should easily reveal flaws, weaknesses, compromises. And while I know the Mach 5.5 has them—because all bikes do—they’re well masked.
I was able to ride the 5.5 with both the stock Float DPS and the optional Float X2 shock. The bike rides well with both, but the X2 provides better suspension performance—it’s more sensitive and more controlled—and the X2’s damping and spring curve are more tunable than the DPS’s. But the X2 is about 100 grams heavier and costs an extra $399.
For the stock Float DPS shock, Pivot’s engineering team has chosen a shock with a tune that can work for a wide range of rider weights. On the trail, this means that heavier, or more aggressive, riders will likely find the bike rides better with more compression damping: that means setting the Open Mode Adjust (the back knob under the blue Open-Medium-Firm lever) to position two or three, or even using the Medium mode (blue lever) for most riding. But is should mean that lighter riders can experience good suspension performance without sending the shock out for a custom tune.
I’m 160 pounds (about 170 in gear and wearing a pack), and I settled on position two (Open Mode Adjust knob) and left it there. The rear end was sensitive and supple, and I never felt the need to use the blue lever on climbs or flatter sections. Position one was more sensitive and supple, but there was a bit too much motion for me: I preferred the improved chassis control of position two. This is in contrast to most bikes which I find ride optimally in position one.
The DPS shock’s spring curve was where I like it: The bike used its travel, but there was still a platform to push off when I wanted to pop the bike. It didn't feel like it was wallowing in its mid stroke, and I never felt it bottom harshly. But it is important to know that the 5.5’s stock DPS shock has the maximum number of volume spacers it already, so riders who like a more progressive air spring will need to explore other shock options with Pivot.
It shouldn’t be surprising to learn that the 5.5 Carbon pedals crisply and feels efficient; this quality is important to Cocalis, which is why Pivot bikes have been this way from the beginning. Whether grunting up a ledgy pitch, accelerating into a hard downhill corner, or powering across chop, the 5.5 is snappy, but still follows the ground well, with no obvious feedback or stiffening of the suspension.
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Descending the 5.5 Carbon was a joy. It was both confidence-inspiring and lively, qualities in a mountain bike that are often at odds.
What made it confidence-inspiring was its phenomenal accuracy, reactivity, and traction. If I needed to put my tire on two-inch wide rock, I knew I could; if I took a bad line and needed to pick the front end up to make a correction, I knew I could; if it was a steep, ledgy, switchback, I knew I could stuff the front wheel in the corner, and it would stick and carve through. The bottom bracket was high enough (plus the suspension doesn’t wallow) that I could pedal up awkward off-camber ledges and through chunky terrain without anxiety, but low enough that I never felt precarious when navigating switchbacks.
Because the 5.5 Carbon was so confidence-inspiring, it encouraged me to take advantage of its liveliness. It accelerates very well; it feels light (I weighed after riding it and was genuinely surprised to see it weighs nearly 28 pounds) and easy to maneuver, and once I got used to the bike’s balance, the front end is easy to pick up. So despite its long front center, slack head angle, and robust parts, the bike is playful, and surprisingly reactive, even at slower speeds. Rather than push back and plow (as I might do on a 29er or a bike I felt less confident on), I would look for opportunities to jump rougher sections, take alternate lines that looked more fun and challenging, and just generally faff around like a kid.
This was my first experience on the 2.6-inch Maxxis tires, and I’m a believer. The traction, control, and feedback were outstanding, without the vagueness, mushiness, or bounciness that I continue to experience from plus tires.
Based on a couple diverse and challenging rides, my first impressions of the Mach 5.5 Carbon are overwhelmingly positive. The bike offers top-of-class performance climbing and descending, and is exceptionally precise. It bumps hard against the enduro category in demanding terrain, but it’s light-feeling, efficient, and sharp-handling when climbing. While the smaller 27.5-inch wheels don't offer the rollover performance of a 29er and made me work harder in demanding terrain, that was somewhat offset by the Mach 5.5 Carbon’s precision, responsiveness, and playfulness. Its one more great bike in the Pivot line.
