The all-new Trek Slash is beefed up in celebration of its sixth iteration.

This fresh design features an oversized, 19-tooth idler pulley and a high-pivot rear suspension configuration for the first time in the model’s lineage. Travel has been increased to 170 millimeters, pushing it further into the all-out, winch-and-plummet ethos that so many enduro bikes seem to be gravitating to. Our 9.9 version was spec’d with Bontrager’s RSL integrated handlebar and stem, a SRAM T-Type XO drivetrain, and the all-new RockShox Vivid Ultimate rear shock.

The previous Slash was an impressive bike. It was impressively light for an enduro bike and was surprisingly efficient to pedal around all day. The new Slash Gen 6 leans more heavily toward the chairlift and shuttle culture side of the mountain bike world with some extra heft and additional pulleys in the drivetrain. However, with the oversized pulley and lighter casing tires, I found the Slash to climb the most efficiently of any high-pivot bike I’ve reviewed thus far. I attribute this mostly to the large, 19-tooth upper idler.

Further, the Slash has a flat anti-squat curve. That is to say, the bike rides squish-free when hammering out of the pedals. Speaking to Trek's product marketing manager, Ross Rushin, about this she said, "Having just the right amount of anti-squat in the system makes this long-travel bike pedal more like a short-travel bike, but don’t worry, there’s nothing short-feeling about it on the way back down." So, the seated position of the bike is fantastic despite having a shorter chainstay length of around 434 millimeters on our size Large mixed-wheel model. The bike keeps your weight firmly between the wheels while climbing steep grades. Despite the (tolerable) extra drag on the climb, you can at least remain well-balanced and comfortable.

Of course, a bike like this isn’t intended for those looking for the utmost in climbing efficiency.  The altered rear axle path that effectively elongates a high-pivot bike’s wheelbase when the rear suspension is compressed is where the chunk-eating magic comes from. The Slash certainly delivers in this regard. Even with a 27.5-inch rear wheel, the Slash provided a surprisingly smooth ride on the roughest trails during the summer dry season. This stout Trek feels most at home when mobbing straight into technical, chunky terrain at high speed. On the first few rides, I felt slightly unsettled by the bike. At first, I thought the feeling might be a potential side effect of the changing wheelbase of the bike. But, after slowing down the rebound on the fluttery Vivid Ultimate, I felt much readier to be on the attack while riding. The Slash does retain an agile quality that I really enjoy, and I was surprised at its ability to tackle slow speed and flat, technical terrain—as well as tight corners—with gusto.

The new Slash is a bold step in a new direction. It is definitely not a bike I would take on a 6,000-foot backcountry loop with my fit friends, but it adds even more ability to charge through fast, straight-line chunk than the already-capable previous version. This ultra-high capability suspension also serves to reduce arm fatigue during huge descents. The new Slash is a standout option for riders looking for a high-pivot setup.