Setting up the suspension on the Slash was fairly easy. All the knobs and settings are easy to reach, and Trek even provides an online guide to help you get started. This was my first time riding a bike with a 170mm RockShox Zeb fork so that was a bit of a learning curve for me on setup. In my previous RockShox 160mm Lyrik I was running 73 psi with 4 volume tokens for my 155lbs mass. I started out with 50 psi and 3 tokens in the Zeb, and it was way too stiff. The front wheel was not tracking well, and the bike was too harsh. After some experimentation, I dialed in my settings at 48 psi and only one volume token, after which things were in a good place. The RockShox Super Deluxe Trek Thru Shaft shock feels great. I found that 155psi, my body weight, was the right amount of pressure on the Slash. More pressure than that felt very harsh and stiff. At 165 psi I wouldn’t use all the travel on drops and compressions that should use all of the stroke.
My first few rides on the Slash were on chunky, square edged, technical climbing with steep, loose descending. I got to know the Slash quite well just on the first ride because the bike was not well suited for the climbing and the descending is exactly what it was made for. This bike has since seen fast alpine, rough and rocky, flowy, and even some days at the Mt Bachelor and Trestle Bike Park.
Starting off with one gripe of the build on the Slash, is that it is spec’d with a 30-tooth front chainring. This gearing ratio left me wanting more on the descents, and if you come to a climb where you want that 30 tooth ring, chances are it’s too steep for the Slash anyways, which I will expand on below. Personally, I would opt for a 32 tooth chainring, and some stronger riders might even prefer to have a 34 tooth ring with the 10-52 tooth cassette. It gives you more gear for the way down, which is where it matters on this long travel race machine.
I left the shock fully open the whole time, preferring to focus on the trail ahead than reaching down for a lockout lever, and didn’t notice too much pedal bob when seated. Certainly not enough to convince me to make the effort to reach down – the Slash pedals very efficiently for a bike of this size. When out of the saddle and cranking hard there is a bit of movement in that rear end, but when you have 170/160mm of travel that is to be expected, and it helps the bike to track and find traction when pedaling through rough terrain on the way down the hill.
The 35mm stem, long wheelbase, and slack head angle made navigating technical climbs a bit trickier than the previous generation Slash. When encountering obstacles during the climb it was necessary to stand or lower my center of gravity more than normal to get some weight over the front wheel. In addition to fighting the wheelbase, as the trail increased in grade, I found myself scooting forward on the saddle to fight the front wheel coming up. As I scooted forward on steep climbs the rear wheel would lose traction easily. This made for a tough balance of weight over the front, but traction for the rear tire. When I hit those punchy 15 degree or more climbs, I found myself walking more than I’d have liked. However, as I got used to these mannerisms and how to manage them, it made less of an impact on my riding experience. If technical climbing is your idea of a good time, you may be served better by an alternative machine. That said, the Slash has gone from more of a trail/enduro bike hybrid to being a full on enduro, long travel rig, as it should be. As we know with these long travel bikes, they are never going to take home the win on the climb. Thankfully the descending prowess makes up for it, and then some.
Unlike the climbing, the descending capabilities of this bike beg for rougher and steeper. The 64.1-degree head angle paired with the 170mm RockShox Zeb provides the stiff front end to plow through all terrain with ease. The length and stiffness of the bike inspire confidence while the somewhat playful nature of the suspension design lets you slash (no pun intended) and jump your way down the trail. While the bike can be playful and it jumps well, it is clear that the main focus is speed, which it maintains incredibly well. When on straighter sections of trail I found myself gaining on other capable riders on comparable bikes time and time again, while feeling composed and controlled. On undulating sections of trail the Slash carried copious amounts of speed up and over rises asking for less exertion, which over the course of a enduro race could add up to shaved seconds. Cornering the bike, it feels responsive with a firm platform to push into and generate speed. The weighting feels well distributed and the traction is plentiful. Only on occasion did I have the front end start to slide when going through flat, loose corners, but the way the bike wanted to break traction in these instances was very manageable. Tight switchbacks were a crux, but aren’t they always…
There is not much to complain about when it comes to the Sram XO1 drivetrain and Code RSC brakes spec’d on this bike. The performance of the bigger dropper post was noticeable on the first ride, giving a definite upgrade over the previous with no issues during the testing period. In the past the notably slack seat tube angle present on the Slash has led to premature wear and stickiness with dropper posts, so it was great to avoid these issues on the new model.
With RockShox’s new Zeb fork up front the bike feels very stable and it tracks through rough terrain very well. The 38mm stanchions are noticeably stiffer and more responsive than the 35mm stanchions on the Lyrik that was spec’d on the previous generation Slash, and it pays dividends when charging hard. The Zeb comes with a little more than a pound increase over Lyrik, but it’s weight worth taking in my eyes. This bike as a whole is about 2lbs heavier than the previous generation coming in at 31.14 lbs with no pedals, which is still a competitive weight in its class, but certainly detracts from its overall efficiency and pedal-friendliness. At 155psi in the rear end with the stock volume spacers I never felt the bottom and the shock felt very smooth. Due to the Thru shaft technology you need to order specific volume reducers, which is far from the end of the world but still something that needs to be considered. I ran 3 clicks of rebound even though it can be set much higher. All the other settings felt very, very fast. There is no full lockout on the shock but there is “lock” and open setting as well as three clicks of compression.
One new design feature that does not function as well as the engineers may have planned is the drain tube directly below the rear shock. The frame creates a little bowl just under the rear shock where water and mud would pool on wet days. In theory the drain tube was a good idea to route pooled water down around your bottom bracket and out through a hole in the bottom of the frame. However, when I first received the bike, I noticed that this rubber tube was loose and rattling around in the frame. In order to put the tube back into place I had to pull out the crankset, remove the bottom bracket (which is threaded, score!), and remove the shock. When placed correctly the tube sits nicely, but the seal does not seem to be overly snug, letting a small amount of water creep under the rubber and into the frame on those really wet days or when washing the bike. I would prefer that there was no drain, and a little bit of water would pool there since it would bounce out when riding. Otherwise, the Slash proved to be a well-considered and high-quality bike all round.