Mountain Bike Action Bike Test: Trek Slash Enduro Bike

Trek Slash
Enduro Bike

The Slash has long been Trek’s solution for enduro riders and racers. For 2021, Trek sought to secure its place as a top contender by updating the new Slash with cutting-edge geometry, practical features such as integrated downtube storage and a suspension system that performs second to none. This month we had the pleasure of putting Trek’s new enduro ripper through its paces to find out if it lives up to the hype.

The Slash features the new RockShox ZEB fork.



One quick glance is all it takes to recognize that Trek has spent many late nights working on the all-new Slash. The frame features time-tested OCLV carbon fiber front and rear triangles, as well as a lightweight magnesium rocker link. Protection is offered by a full downtube shuttle guard and an integrated chainstay protector to minimize chain noise. A Flip Chip allows riders to select their desired geometry, with half a degree of head tube and seat tube angle adjustment between the high and low settings. New for this year, integrated downtube storage allows riders to tuck snacks, tools or tubes inside of the frame for easy-to-access storage. The frame is finished off with Trek’s Control Freak internal cable routing system to maintain a sleek look with mess-free cables.

The slack front end with 170mm of travel allows riders to confidently roll down anything.



The Slash 9.9 X01 is Trek’s flagship model and will set potential buyers back $7999. For riders looking for a more wallet-friendly option, Trek also offers the aluminum-framed $3999 Slash 8, as well as a number of other trim levels to meet many riders’ budgets. Our top-spec test rig came equipped with the latest iteration of SRAM’S X01 Eagle drivetrain and features an easy-on-the-legs 10-52 tooth cassette.

Bontrager tires wrap the new Line 30 Carbon wheelset and keep the bike rolling fast and smooth. Bump absorption is handled by RockShox’s new Zeb Ultimate fork and Trek’s own RockShox Super Deluxe Ultimate ThruShaft rear shock. The cockpit is finished off with Bontrager components to ensure the rider is comfortable for long days in the saddle.

Trek designed a heavy-duty frame protector that runs nearly the full length of the downtube. And, if that’s not enough, an MRP bash guard was added for good measure.



Trek stuck with 160mm of tried-and-true rear suspension travel but chose to spec a 170mm-travel fork up front to meet the demands of its hard-charging enduro racers. The new RockShox Zeb fork features 38mm stanchion tubes and beefy lowers to aid in handling precision. Out back, the proprietary Super Deluxe ThruShaft aims to offer stellar small-bump compliance, support through the mid-stroke and great bottoming resistance, all while remaining responsive to rider input. At both ends, a solid range of usable adjustments makes suspension setup a breeze.

The Slash may be made for speed, but it’s not scared to boost trail features.



The Slash is built for enduro racers but could appeal to trail riders wanting a plush ride with lots of storage options. The Slash is designed for the rider looking to push its long legs up the trail and fly back down with speed and style. Big jumps and high-elevation mountains are where the Slash shines best.   


While the Slash is probably not ideal for chasing down KOMs on your local XC trails, its climbing abilities are more than adequate for an enduro race machine. Lightweight carbon wheels and fast-rolling rubber contribute to the bike’s climbing performance. Unfortunately, the shock did not do the Slash many favors in the climbing department. In its open position, the rear end displayed a noticeable amount of pedal bob, significantly more than some of today’s best-climbing enduro bikes. This rear end, coupled with long 175mm crank arms and a low bottom bracket, makes pedal stroke timing crucial on rocky trails. On the flip side, with the shock lever in the firm position, the rear end felt virtually locked out. This locked-out feel was great when pedaling on pavement or smooth fire roads but hindered traction and ride quality on more technical singletrack climbs.


The Slash is happiest when the trails point down and the race clock starts. Its overall downhill performance is topnotch, due to its stiff chassis and well-thought-out geometry. The bike offers an intuitive and predictable feel down the trails and an outstanding suspension platform that encourages riders to send bigger gaps and huck the most intimidating drops. The Slash continues to appeal to hard-charging racers, leaving some casual riders finding it too stiff; however, it can be tuned to find a setting that will work for everyday trail riders.

The proprietary RockShox Super Deluxe ThruShaft complements the Zeb fork, and together they provide a great overall package. The suspension offers more support and a firmer feel up top than some other enduro bikes on the market without feeling harsh or unforgiving. This Trek can handle hard compressions with a level of composure nearly unmatched by its competition. This allows the rider to throw the bike around as if it were a light-duty rig without giving up confidence in the most demanding sections.


We were blown away by the performance of Trek’s latest Slash, but there is some room for improvement. Unfortunately, by the end of our first ride, the Slash had already developed some creaking noises in the rear end. A few of the linkage bolts had begun working their way loose. Re-torquing these bolts to Trek’s spec improved the noise to some degree, but it did persist under hard pedaling. By today’s standards, the Slash is a little loud in the roughest sections of trail due to chain slap. This can be remedied at home by sticking some rubberized tape on the existing chainstay protector to add a bit of extra sound dampening. The 820mm-wide Bontrager handlebars that come stock on the Slash are wide by any standard. Because of this, many riders will likely choose to bust out the hacksaw and cut the bars down to a more modest width.


The Slash is first and foremost an enduro race bike built to get riders down the trail as fast as possible while retaining the ability to pedal between stages. The rider best suited for the Slash is one who isn’t afraid to put in work on the climbs, knowing he will be heavily rewarded when the trails point down. This long-legged 29er loves to be ridden hard and wants a rider who will push it during every descent; however, with some suspension tuning, this Trek could be set up for a more causal rider looking for a forgiving feel on rough trails. Overall, the Slash is a hard bike to beat within its category and is likely to earn some medals as racing returns in 2021.


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