TREK SLASH GEN 6 REVIEW

There has been a Slash in Trek’s arsenal for just over 10 years, and it has undergone five generations of upgrades coming into the end of the 2023 season. This time, however, Trek didn’t just upgrade the Gen 6 Slash, 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, which was hinted at in their bike releases the last few years. 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, both of which carry into the sharply engineered Gen 6 Slash.

FRAME

Trek’s signature OCLV Mountain Carbon is employed in the construction of this frame, making up both the front and the rear triangles. Dual-density downtube protectors guard against rocks and tailgate damage, and an extensively engineered chainstay protector helps keep the bike quiet when things get rough. Under the clear coat of paint on the downtube, they’ve added an impact-resistant film that acts as frame protection against light damage. They upgraded their storage box with a wider mouth opening and contained the cables and hoses in their own tubes to eliminate snag points when taking out the storage bags inside the frame.

The bike is only sold with a mixed-wheel setup, but the bolt-on shock mount can be swapped to allow a 29-inch back wheel to be used without changing the bike’s geometry—this goes for all sizes except size small, which is only available with 27.5-inch wheels. It comes from the factory with a neutral headset cup, which gives the bike a head angle of 63.3 degrees and an effective seat tube angle of around 77 degrees depending on which size you get. You can get an angle-adjust headset cup that will steepen or slacken the bike by 0.7 degrees. Our M/L-size test bike has a 434.2mm chainstay length, but Trek gives this bike size-specific chainstays to keep a consistent ride feel throughout the size range.

SUSPENSION

Trek has jumped on the bandwagon of high-pivot bikes with the allure of the rearward axle path that they claim allows the bike to carry speed more effectively throughout the trail, specifically on square-edged rocks. They’ve combined this 170mm-travel high-pivot system with their existing ABP (Active Braking Pivot), which they say allows them to separate the anti-squat and anti-rise characteristics and tune them individually. This system is designed to keep the suspension active even under heavy braking, keeping traction to the rear wheel at a premium.

According to Trek, they’ve been able to keep the anti-squat number at just over 100 percent throughout the stroke. This basically means the suspension won’t be affected by your pedaling movement no matter where you are in the bike’s travel.

This Slash has a couple of other tricks up its handlebars with a rear suspension flip chip to adjust the progression located in the bolt-on shock mount at the base of the shock. This is the same bolt-on mount that can be swapped out to accommodate a 29-inch rear wheel. Our test bike came spec’ed with RockShox’s new Vivid Ultimate high-volume air shock with an adjustable hydraulic bottom-out, a climb switch, and high- and low-speed compression adjustments.

This is matched to a 170mm-travel RockShox Zeb Ultimate fork with the Charger 3 RC2 damper with high- and low-speed compression adjustments. They’re saying this bike is compatible with up to a 190mm fork with a 606mm axle-to-crown measurement if you decide to make it more of a park bike.

COMPONENTS

The Slash 9.9 XO AXS T-Type build, which we tested, featured the excellent SRAM XO AXS Transmission, Code Silver RSC brakes and a 170mm-travel RockShox Reverb AXS dropper post. This bike has a unique chain line consisting of an oversized 19-tooth upper idler pulley, an MRP bash guard and lower idler pulley, and a 30-tooth chainring attached to 165mm XO cranks. I

t also contained some Bontrager components in the mix with the RSL integrated handlebar/stem system, grips and saddle, along with Line Pro 30 carbon wheels wrapped in a Bontrager SE6 Team Issue front tire and a SE5 Team Issue rear tire. This wheel and tire combination we felt was a weak point of the bike because we broke a spoke nipple on the third ride out and just couldn’t get comfortable with the grip the tires offered.

Trek offers several build options for the Gen 6 Slash, including the aluminum Slash 8 that starts at $4,400 and includes every feature the Carbon 9 models have. From there, they go up in price and build spec with every size—from S, which is 27.5 inches only, to M, M/L, L and XL, all of which are mixed-wheel builds topping out at $11,500 for the Slash 9.9 XX AXS T-Type build.

CLIMBING

For a high-pivot bike, the Gen 6 Slash is an excellent climber. We were impressed with the ease of forward momentum when the trail pointed uphill. We did some experimentation with the progression chip at the base of the shock and found that, though the climbing performance was enhanced, it wasn’t enough for us to want to flip it every time we rode mellower trails, as the bike performs perfectly well in the less progressive setting. Steep technical sections were a pleasure to climb, and generally boring road climbs and traverses seemed to pass more quickly than normal aboard the Slash. Though we flipped it once just to see if it helped, we never felt the need to use the shock’s climbing switch.

We were impressed with the bike’s composure on any ascent. We also liked how the shorter 165mm cranks worked with the 27.5-inch back wheel, giving us both ground clearance in sticky situations and the quick acceleration we associate with mullet bikes. We never had a pedal strike while riding this bike, which made pedaling along narrow shelves and up technical bits a more peaceful experience.

DESCENDING

Aside from experiencing some technical malfunctions, none of which have anything to do with the frame, we were more than happy with the descending performance of the Gen 6 Slash. Our initial impression of high stability continued on through the duration of the test as we pushed limits and enjoyed each second of riding this bike.

For the first few days on the bike, we felt a strange flex in the back of the bike that we thought might have been associated with frame flex due to experiencing an intense squeaking when rounding sharp corners at speed. We figured out later this was an unfortunate combination of the flimsy-feeling Line Pro 30 rear wheel flexing and a sticky piston in the brake caliper rubbing the rotor in an annoying fashion.

As soon as we troubleshot these issues, we were able to experience the full descending potential of the Gen 6 Slash. It’s one of those “The faster you go, the better it feels” types of bikes that encourages less brake usage. When you are eventually forced to use the brakes, the suspension responds as if you’re not and remains as active and supportive as ever.

We found ourselves late braking into all kinds of corners and whipping around them faster than we’d normally have done, ready to face the next one. We also felt the bike’s composure on the steeps and in intense rock gardens, which it skipped or floated through rather than getting hung up in the crevasses. When we experimented with the progression switch, we found the added support to be a little too much on all but the most mellow sections of the trail and quickly flipped it back, as we were more than happy with the performance in the less progressive setting.

WHAT DID WE LOVE?

There was a lot to love about this bike that we feel needs a shout-out. Most of our testers loved the 165mm XO cranks and wished more companies would add 165mm cranks to their bike’s specs list. RockShox’s new Vivid Ultimate shock was excellent throughout testing, taking very little time to set up and even less time to adjust for added comfort and traction. We were also impressed with the bike’s overall stability and maneuverability wherever we were on the mountain, bringing the confidence of a big bike and the joy of a smaller bike.

WHAT DID WE HATE?

This might be a bit longer than normal, and that’s mostly due to the Bontrager products supplied with this bike. Aside from the grips and the saddle, we didn’t particularly like any of them, especially the tires and rear wheel. While they performed adequately enough to have fun on the trail, we never quite felt the confidence in grip that we feel when a Maxxis Minion or American Classic Vulcanite is mounted to the wheels.

The rear wheel was a whole problem in itself, because while the hub action was good, the wheel as a whole flexed far too much for comfort, and we even broke a nipple at the bike park on just the third day riding the bike. The RSL integrated bar and stem didn’t have the adjustability we’d prefer, and most would have liked to roll the bar angle back just a little bit if they could. The BITS headset tool proved to be useful, but very hard to get out of the head tube when needed, which was annoying.

Our other complaints were about the fork and rear brake, both of which could happen to any build. The rear brake suffered from a stuck piston and was very far over to one side, meaning the rotor rubbed on the caliper itself. This was an easy fix. The fork formed a weird clunk in the rebound stroke, which made it hard to ride at any speed, so we had to get a warranty replacement to complete the test. All of these things gave us a bit of a love/hate relationship with the bike more severe than with most bikes. Were we to own this bike ourselves, these would have been warranty issues or we’d simply swap out all the troublesome parts and enjoy the excellent performance this frame can offer.

BOTTOM LINE

Our feelings about the Gen 6 Slash may be mixed, but the good outweighs the bad, and we were able to get past the inconveniences. This bike is very versatile in the gravity side of things, so if you’re looking for an enduro race bike, backcountry exploration rig or park sender, the Slash has you covered. A quick swap over to your preferred parts and this bike will serve its rider well for a long time. Because of the component’s spotty performance, our recommendations are damped on this particular build, but we feel it’s still well worth consideration when looking for your next full-send rig.

TREK SLASH 9.9 XO AXS T-TYPE

www.trekbikes.com

CATEGORY: Enduro

SUSPENSION: 170mm (front/rear)

TIRE SIZE: 29″/27.5″ mixed

Price: $9,400
Weight: 34.7 pounds (without pedals)
Sizes: S, M, M/L (tested), L, XL
Frame tested: 170mm, OCLV Mountain Carbon (travel and material)
Shock: RockShox Vivid Ultimate
Fork: RockShox Zeb Ultimate
Wheelset: Bontrager Line Pro 30 carbon
Tires: Bontrager SE6 Team Issue (29×2.5″) front, SE5 Team Issue (27.5×2.5″) rear

Seatpost: RockShox Reverb AXS (170mm travel)
Saddle: Bontrager Arvada
Handlebar: Bontrager RSL integrated handlebar/stem
Stem: Bontrager RSL integrated handlebar/stem
Grips: Bontrager XR Trail Pro
Headset: Integrated cartridge bearing
Brakes: SRAM Code Silver
Rotors: SRAM 6-bolt 200mm (f), 200mm (r)
Rear derailleur: SRAM XO AXS Eagle, T-Type
Shifters: SRAM AXS POD Ultimate
Crankset: SRAM XO Eagle, 165mm
Bottom bracket: SRAM DUB, 73mm, BSA threaded
Cassette: SRAM Eagle XS-1295, T-Type, 12 speed, 10-52T
Chain: SRAM XO Eagle, T-Type, 12-speed
Chainrings: SRAM XO T-Type, 30-tooth

GEOMETRY SIZE M/L

Head tube angle: 63.3°
Effective seat tube angle: 77.3°
Reach: 468.1mm (18.4″)
Stack: 632.1mm (24.9″)
Bottom bracket height: 351.1mm (13.8″)
Chainstay length: 434.2mm (17.1″)
Wheelbase: 1253.2mm (49.3″)