This is the enduro bike other enduro bikes are scared of


There has been a Slash in Trek’s arsenal for just over ten years, and it has undergone five generations of upgrades coming into the end of the 2023 season. Trek didn’t just upgrade the Gen 6 Slash, however; they completely reimagined it. It goes without saying that the new Slash is longer and slacker than the previous generation, but Trek had a few other things up its sleeve, all hinted at in the last few years of bike releases. We saw the high-pivot come into form on the Session in the 2022 model year, and earlier this year the release of the Fuel EX showcased Trek’s interest in engineering diversely adjustable bikes.

The Slash 9.9 XTR is sure to be a beast on the trails with its 170mm of front and rear travel, mixed wheels, and aggressive geometry; just don’t get it dirty too fast.

Just by looking at the two generations side by side, you can see how the engineers at Trek fully redesigned the Gen 6. It no longer has a low-slung sports car look, but is poised more like a gorilla that is ready to pound the trail into submission. The only thing that is really similar between the two bikes is the internal storage and Trek’s continued use of the ABP (Active Braking Pivot) suspension design.


As it has a high-pivot suspension design, you might say Trek is jumping on the suspension progression bandwagon. They have a ready response to that accusation, however, and it’s not what you might think. They’re saying it helps with pedaling efficiency more than anything else, though it does have other benefits as well. They’re claiming they were able to achieve an over 100% anti-squat value over the entire suspension stroke as you pedal, meaning this bike is an even more efficient pedaler than their most recent Top Fuel. It’s hard to dispute the graphs, but we’re going to be testing for ourselves whether this is true or not.

Aside from enhancing the pedaling characteristics of the bike, the high-pivot system is also supposed to help with keeping momentum moving forward on the trail. They’re saying the rearward axle path moves with the bumps without hanging up on them and robbing speed. With this system comes two idler pulleys with the upper one being an oversized 19-tooth pully that is supposed to help eliminate pedal kickback and help determine the anti-squat values. The lower pulley is there to mitigate chain growth beneath the chainstay and prevent major tugging on the derailleur; this, they say, helps with a smoother drivetrain performance and means the suspension isn’t fighting against the derailleur’s clutch.

The ABV (Active Braking Pivot) is carried over from Trek’s previous models and is used on all of their full suspension models aside from the Supercaliber, which we talked about a few weeks ago. They say this technology helps keep the suspension active when it’s needed most and gives Trek the ability to tune the anti-rise and anti-squat properties independently. With all of this new technology, Trek decided to up the Slash’s rear suspension travel from 160mm to 170mm. They’ve also added a flip chip to adjust the suspension’s progression at the base of the shock itself and have done away with the Mino Link.

We’ve talked a lot about suspension, but that’s not the only thing that has been improved upon. With the Slash Gen 6, Trek has decided to offer it only as a mixed-wheel setup on sizes medium and up, with the option later to throw on a 29” rear wheel if desired; size small is full 27.5” only. Along with that change-up, they decided to give it a slacker 64.5-degree head angle, a steeper 77-degree seat-tube angle, size-specific chainstays, and an increase in dropper insertion by around 80mm, depending on the frame size. With separately purchased angle adjust cups, you can make it 1-degree steeper or slacker when desired.

They’ve also taken a few more steps to protect the frame itself, like putting replaceable dual-density downtube guards to protect from rocks and tailgates, adding an impact-resistant film under the paint for added protection of the carbon fiber, and throwing on a rear fender to protect the suspension linkage and other parts of the frame; this, however, can only be used with a 27.5” rear wheel. They’ve also made updates to the internal storage, like making the opening bigger and the latch easier to reach.


The calm before the storm, or after in this case. This was taken right before we boarded the beast and began shredding the sloppy slopes of Brian Head Resort in Utah.


Being that we spent most of our few days on this bike at the lift-assisted bike park of Brian Head, Utah, we don’t have many climbing miles on it. But, based on what climbing we have done, we can say this bike feels pretty good when the trail points up. It had plenty of traction to get up some steep loose punches and was comfortable and efficient enough to hold a decent average speed with minimal effort. So far, we haven’t felt the need for the climbing switch, but we’ll be experimenting more as we continue to test the Gen 6 Slash.


Our first experience piloting the Gen 6 Slash down a mountain was in Brian Head, Utah, after a particularly long-lasting and aggressive monsoon storm, which meant the trails were sloppy and muddy and the rocks as slippery as ice. The bike performed beautifully on this terrain, remaining poised and stable through the slick corners and rock sections. We were able to carry speed effortlessly through each section with the support of the suspension allowing us to pump rather than pedal to keep us going. Corner grip was a non-issue even on the slickest corners where we were sure we’d slide right up the berm; and even when we did slide, it was controlled and predictable. The bike was very easy to turn and went where directed with enthusiasm and plenty of grip.

Smashing through rock sections, the bike felt light on its feet and ready to respond to subtle direction changes, all while feeling stable and unwavering when thrown an unexpected curveball. Even under heavy braking on the steepest sections the bike was alive, and we were in control with no scary sliding or unnecessary wheel lockups; this allowed us to look ahead with more confidence to scope the next obstacle.


The fork was great until it wasn’t. A strange clunking sound in the beginning rebound stroke made it hard to hold on during extended descents.

There are a few things that made their presence known that need to be addressed. The Fork developed a clunk in the rebound stroke that made it hard to hold onto during longer descents, but we feel this is more of a RockShox problem than a Trek problem. We also experienced some frustration with the rear brake caliper, but again, not a Trek problem. The only thing we weren’t sure of on the bike was the flex we experienced in the rear end of the bike. This isn’t something we disliked particularly, but it has caused a little concern and is something we’ll be keeping an eye on as the test continues.

The Slash 8 is the cheapest version in the line-up and the only alloy option currently offered.


Trek starts with the Slash 8 which is the aluminum version at $4,400 and then goes full carbon with the Slash 9 GX AXS T-Type priced at $5,800. Our test build was the Slash 9.9 XO AXS T-Type priced at $9,400 in the medium/large size. Trek also offers various models with Shimano drivetrains—one with XT and the other with XTR. Their highest-priced build goes for $11,500: the Slash 9.9 XX AXS T-Type. All build options are offered in sizes small, medium, medium/large, large, and extra large.


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