Field Test: Trek Slash – Rides like a session

In keeping with the updates made to the Fuel EX last year, the new Slash has plenty of modifications that the end user can make. Push-on headset cups allow you to slacken or slope the head tube 1 degree in any direction, and a replaceable lower shock mount fits either a 29-inch or 27.5-inch rear wheel, with a flip slide located in it to switch between high and low shock development modes. All of this makes the bike really capable of shifting, but for the sake of this test, we kept things at the hybrid wheel, and the stock 63.3-degree head angle setting.
The seat angle is around 77 degrees, depending on size, with the chainstay length also varying to accommodate front end growth. These chainstay lengths depend on whether you’re running mixed or matched wheel sizes, but assuming the dimensions are as follows: S, 429mm; m, 429 mm; average/L, 434 mm; l, 434 mm; XL, 439 mm. These may look a little short on paper, but it’s important to remember that due to the high axial layout, they grow a bit when slouched and during travel. At sag the wheel is about 11mm rearward, and at full extension the chainstays are 19mm longer than the fixed number. With the bottom bracket lowered by 27mm, the center of gravity is set exactly on the diagonal line, maximizing the cornering stability that the increased wheelbase can provide.

Both the carbon and aluminum models get well-arranged storage space inside the frame, as well as some top tube bottle caps, if you want to carry all the stuff inside and on your bike.

climbing

With 170mm of travel front and rear, it’s safe to assume that climbing the Slash will be a bit of a challenge, but a lot of work has been done to make sure getting to the top wasn’t a huge chore. The ratio you chose. With extremely consistent anti-squat across the entire gear range – hovering above 100% when sagged – the Slash climbs comfortably and consistently, providing enough support to ride high, while still absorbing bumps along the way.

There’s definitely some extra drivetrain noise associated with the idler pulley and lower chain pulley, but thanks to the higher tooth count on that upper idler, it’s not too extreme. I’ve spent some long days pedaling on the Slash, and I’ve never found myself hating the experience—it’s more than happy to ride along a logging road just as it’s as eager to cram the technical parts of the trails.

We’ve done the brutal math, and although the idle bikes feel a little slower over the course of long climbs, the Slash makes up for that extra drag with an even pedal platform and good body position that keeps you comfortable over long distances.

Descending

There is a widespread assumption that the gains of a high-axle bike are achieved at the expense of overall maneuverability and liveliness in slower terrain. There are some exceptions to this claim, the most important of which is the new Slash. This bike can happily tear up chunky sections of trail, but it’s also able to sense when things get tight and slow, thanks in large part to carefully considered geometry and a very predictable suspension feel.

Predictability is key to the bike’s overall versatility, as you can push the suspension into smoother terrain without feeling like you’re losing too much power in the back end. This support builds well into the mid-stroke, meaning the bike retains a soft feel for excellent small-bump performance and grip. The overall feel is biased towards that latter end of the spectrum, which to me is what you’re probably looking for if you’re in the market for a 170mm-high gimbal.

Jumping feels natural and intuitive on the Slash, and although the bike may lack some of the Ibis’ coolness, it still manages to feel fun and lively on smaller sideways hits and natural oversteers. The Trek feels as if its penchant for speed dictates certain terrains you want to steer it to, as it really comes alive when you’re pushing hard on really tough trails.

As a complete package, the Slash is a solid and precise bike, perhaps too much for some who want a more forgiving frame. The one-piece carbon bar/stem assembly plays a big role here, imparting a greater amount of feedback than a traditional cockpit, but the Bontrager Line 30 wheels are also fairly stiff. The latter didn’t bother me, as they held their line well and eliminated a lot of the hard hits and corners that the bike is so keen to take.

Trek did a pretty good job of making the Slash a quiet bike, and then seemed to lose the plot when they specified a hard rubber guard that doesn’t do much to dampen drivetrain noise in rough terrain. I replaced the stock rubber with a bit of STFU tape, and found that the bike went from rattling during successive hits to performing in near silence, making the ride much more enjoyable.

Technical report

MRP MXg Series Guide: This seemingly innocuous lower roller has perhaps proven to be the most controversial element of the new ride, given the issues a fair number of early users have had with the chain falling off the roller during fairly normal riding scenarios. This happened a few times during testing, both at the bike park and on the area’s low-speed tech trails — all of which led to some frustration.

After communicating with Trek and MRP, it became clear that the guide was installed incorrectly from the factory, with 5mm spacers instead of the intended 7mm between the frame and the guide. It didn’t seem like 2mm would make much of a difference to me, but after changing the spacing and taking the bike to Pemberton for a huge weekend of riding, I wasn’t able to drop the chain again. The passages there are hard, fast, and full of chain-challenging moments, so things can be constant forever.

RockShox Vivid Ultimate Shock: In many ways, the Slash feels like a showcase bike for how well Vivid can perform. Its dead-silent operation and excellent damping suit the bike well, and the shock’s tone feels ideal for a wide range of riding styles. With visual and relatively simple adjustment, finding your happy place in clickers is easy and intuitive.

RockShox AXS Reverb Seatpost: The Slash has an impressively long entry depth, but none of that is put to good use in specifying the AXS Prism, which only wins points in the cockpit cleanliness department. In addition, the AXS posts are prone to developing sag, which happened within the first few days of testing. You can bypass the post fairly easily, but not having to do so in the first place would be a better suggestion.