An affair of dirt and rubber.
The affinity we hold for plus tires is somewhat akin to a love affair. While we've seen nearly every possible version of the platform, we remain enamored with its generous qualities that keep us feeling comfortable and confident on the bike, planted when loose corners try to take life for a spin, and cushioned from the big hits that can leave our hearts feeling battered and bruised. In this particular romance, it's really quite a classic story, but with an extra —ahem— Boost. The 2018 Pivot Switchblade Carbon 27.5+ XT/XTR Pro 1x takes its own salacious twist on the classic Boost meets tire clearance love story that we read to our children at night, with the extra addition of super-wide hub spacing, and all-mountain hungry geometry ready to tear things up with its plush and girthy grip.
There's a lot going on with this bike, and we'll get to that, but the real naughty element lies in the introduction of what Pivot is calling Super Boost Plus 157, a new rear axle standard that adds an additional 9mm to the rear axle and 12 fecund millimeters to tire clearance. Given the implications of a frame with such titillating clearance, we're a little surprised—even disappointed—that Pivot didn't call the new standard a sexle. Whatever the case, it essentially combines a DH chainline with a typical 5in bike's Q factor and heel clearance. The introduction of a gravity-sized rear axle has serious implications for an aggressive enduro rig, and these implications go well beyond the increased rear wheel stiffness of the more acute spoke angle.
The key effect of the sexle—err, Super Boost rear hub is that the Switchblade enjoys the clearance to run traditional 29ers or, as is the case here, add an additional element of forgiving, save-your-ass squish with 27.5+ wheels and tires. Either way, the extra-wide spacing allowed Pivot to get freaky with chainstay lengths, chopping them down to 16.85in by moving the rear wheel up towards the seat tube. That's a dimension that makes standard Boost axles blush, and it pairs with a Phoenix-inspired, double wishbone rear triangle to stiffen both the pedaling interface and the linkage design. Increased efficiency and decreased pivot bearing wear—what more could you ask for in an off-road partner?
The rest of the geometry is similarly capable. Where the concise back end makes for a sharp knife while dicing rooty sections, the enduro-minded head tube and bottom bracket height make for a slack, low chassis that complements the 2.8in tires with a devil-may-care, flippant promiscuity in the face of questionable lines. The Switchblade provides a platform of stability when a series of poor life choices on the trail has you confronting big hits and roll overs at impolitic speeds. Despite the frame's big-line parachute qualities, its seat tube sits relatively steep, keeping you forward and on top of the pedal stroke while climbing. That's a little slacker than the Mach 4, but—when the grade flips and the rocks rise to meet you—the Switchblade will leave any XC race whip for dead.
Pivot prides itself on build kit specs, and the Pro build on this bike is no exception. The primary feature is Shimano's XT M8000 group, with spots of elevated XTR componentry. Scrappy, familiar names like Race Face and DT Swiss round the build out, and the frame is deckedout with either a KS LEV Integra (size XS) or Fox Transfer (small-XL) dropper that tailors saddle height to whatever ups and downs you happen to encounter on the trail.
- An aggro trail bike with unprecedentedly stubby chainstays
- 135mm of DW-Link suspension maintains pedaling throughout travel
- Long, slack geometry bails you out on bigger than expected lines
- Gravity-inspired Super Boost rear axle for added tire clearance
- Elements of the DH Phoenix reinforce the rear linkage
- Plus-sized tires add cush and traction
- Full carbon construction is light and efficient