Trek Slash 9.9 X0 AXS T-Type review

Trek’s new Slash 9.9 X0 AXS T-Type is even burlier than its predecessor. It features more travel, slacker geometry, rolls on mixed wheels (29in front, 27.5in rear) and features a new high-pivot suspension platform.

For anything gravity-related, Trek believes the Slash will have you covered.

But, is it all thrills and spills for the new Slash? I flew to Canada to test the bike in Whistler's notoriously techy Creekside, then rode it in the UK on my familiar test tracks to see how the Trek handled.

Praise needs to be given to the bike's pedalling performance, considering its stats on paper. It’s not the 'meathead' you might expect when on the trails. However, a few tweaks such as a shock re-tune may be needed to release the Slash’s high-pivot potential.

Trek, it seems, has made efficiency, rather than bump-swallowing comfort, its priority.

That means the new Slash should suit riders wanting to head off the back of beyond and equally to the bike park, with a stable, predictable-handling bike.

Trek Slash 9.9 X0 AXS T-Type frame and suspension

Trek has a successful history of high-pivot bike design, with the Session downhill bike adopting this configuration in 2021. The Slash's journey into high-pivot design spanned several years and multiple iterations as Trek worked to fine-tune the implementation.

The new high-pivot Slash provides a generous 170mm of rear-wheel travel, focusing on delivering a rearward axle path for smoother bump force absorption.

Notably, there's about a 19mm maximum rear-centre growth at 135mm of travel, which transitions to a forward axle path for the final 40mm, finishing 17mm behind the axle’s starting point.

This design is intended to prevent hang-ups on square-edge obstacles and improve trail momentum. At 30 per cent sag, the chainstays extend by approximately 11mm compared to the static geometry chart.

An oversized 19T upper idler helps reduce drivetrain friction and is used to reduce pedal kickback by managing chain growth during compression by routing the chain close to the main pivot.

Careful attention has been given to preserving pedal efficiency and maintaining anti-squat performance above 100 per cent throughout the Slash's full travel.

Additionally, you can adjust the bike's leverage rate with a flip chip on the lower shock mount, offering a choice between 20 and 25 per cent.

A lower idler, developed in collaboration with MRP, effectively counters chain growth below the chainstay. This enhances suspension sensitivity and makes drivetrain shifting smoother by reducing undue tension on the derailleur's cage.

For chain replacement, the new design accommodates a standard 126-link chain in all sizes except the extra-large, which uses a 128-link chain. If owners of the extra-large want to replace their chains, they will need to buy two and join them together.

Despite these updates, Trek retains its ABP pivot (Active Braking Pivot) at the chainstay/seatstay junction, providing its familiar concentric rotation around the rear axle. The Slash maintains its identity as a single-pivot, linkage-driven shock platform.

In the latest Slash, Trek has retained its OCLV Mountain (Optimum Compaction Low Void) carbon fibre frame.

This construction is designed to bolster the carbon's strength. However, it features a neat addition – Integrated Carbon Armor, a hidden protective film layer beneath the paint, providing extra safeguarding for the carbon.

The new replaceable fenders under the down tube are intended to shield against rocks and impacts. One guards the bottom bracket, while the other offers protection from pick-up truck tailgates.

There's also a rear fender integrated into the bike's design, matching the styling of modern front fenders. It's worth noting that this rear fender fits the 27.5-inch rear wheel and needs to be removed if you switch to a 29-inch wheel.

Another nice touch is the new chainstay protector, designed to reduce chain noise by minimising both vertical and lateral chain movement.

As for internal features, while you won't find internal headset routing, Trek has introduced new internal cable guides, called 'Chunnels', to tidy up the Slash and maximise internal frame storage space.

Its internal frame storage has a new hatch with a larger opening for easier item storage, and the compartment's opening lever is now more accessible.

Trek has also made an eco-friendly choice by using recycled plastic for the internal frame storage parts.

In terms of standards, the Slash 9.9 features Boost 12x148mm rear-hub spacing, a threaded bottom bracket shell and a 55mm Boost chainline.

The rear brake is equipped with a minimum 200mm flat mount, capable of accepting a 220mm maximum rotor size.

Trek Slash 9.9 X0 AXS T-type geometry

For the Slash, there are five sizes available: small, medium, medium/large, large and extra-large. These sizes offer the expected geometry for a rugged single-crown bike.

For testing, I opted for the medium/large (M/L) frame. The bike features a slack 63.3-degree head tube angle, a contemporary 77.3-degree effective seat tube angle and a reach of 468mm, making it well-suited for demanding trails. With a stack height of 632mm, it should feel confident on steep descents.

The chainstays are short, starting at 434mm. However, these extend by 11mm at 30 per cent sag, thanks to the rear axle path. Larger L and XL bikes have size-specific rear centres for a tailored fit.

With a 605mm effective top tube, the Slash should offer a comfortable upright seated position for those extended rides. The 351mm bottom bracket may not be the lowest in the enduro bikes category, but it strikes a balance between agility and pedal efficiency on techy trails.

Trek Slash 9.9 X0 AXS T-type specifications

This bike is loaded with some impressive kit. It sports RockShox’s ZEB Ultimate and Vivid Ultimate suspension, along with SRAM's X0 Eagle AXS T-type drivetrain.

It relies on SRAM's Code Stealth Silver brakes with 200mm SRAM HS2 rotors to manage speed.

The rest of the bike is decked out with Bontrager components featuring plenty of carbon fibre.

This includes its Line Pro 30 wheels and a Bontrager RSL Integrated handlebar/stem.

Trek has shrouded the Slash’s wheels in Bontrager’s SE6 and SE5 tyres. Completing the build, this model features a RockShox Reverb AXS dropper seatpost for some extra electronic tech.

All this tech and carbon makes for a respectable weight of 15.79kg for a long-travel bike in a size M/L without pedals.

Trek Slash 9.9 X0 AXS T-Type ride impressions

I rode the Trek pre-launch at Whistler’s Creekside bike park with its Enduro World Series stages, and tech blue, black, and double-black trails.

I also had time on the bike around my local test trails in the Forest of Dean and at BikePark Wales to get a feel for the Slash.

Trail conditions varied from fully dry to typically British and damp, making the roots, rocks, mud and hardpack surfaces range from ideal to slick and slimy.

Setup

Getting the Trek’s suspension settings to the best place I could for me was pretty straightforward. However, that doesn’t mean it’s the best the Slash can be; a shock damper retune would release plenty more potential.

For my 75kg kitted-up riding weight, I set the shock pressure to 180psi to get 30 per cent sag. Low- and high-speed compression were set fully open, five clicks from five, to maximise sensitivity.

I ran the rebound at six clicks open from 18, and this was still plenty fast enough. Finally, I preferred the HBO (Hydraulic Bottom Out) in its middle position of five.

I pressured the fork to 64psi, which was 8psi higher than RockShox’s TrailHead app suggests. Low- and high-speed compression were run fully open, and rebound was set to 14 clicks from closed out of 18.

However, I didn’t feel much difference in rebound speeds between 12 clicks from closed and fully open, whatever setting I used.

I inflated the Bontragers to my usual tyre pressures: 21psi and 25psi front and rear respectively for natural trails, and 24psi and 28psi for the bike park.

Overall, this gave me a balanced bike that I felt comfortable on.

The cockpit was easy to get sorted with SRAM’s Code levers and AXS pods.

The integrated cockpit isn’t built with my preferred handlebar shape, but I could get the handlebar height where I need it easily enough.

Trek Slash 9.9 X0 AXS T-Type climbing performance

Trek has done a praiseworthy job of making the high-pivot, 170mm-travel Slash remarkably efficient when it comes to pedalling.

Considering its additional idlers and longer chain, there’s no discernable difference between the Slash and other enduro bikes.

Trek has certainly positioned itself as a market leader when it comes to climbing efficiently in this market.

The secret to this bike's pedalling prowess lies in a combination of factors, though. Trek's choice of the Vivid shock with RockShox's firmest compression tune provides ample support to the suspension, preventing the shock from sinking deep into its travel.

The inclusion of fast-rolling Bontrager tyres influences the climbing experience, and the Slash's kinematics and minimal idler resistance enable it to keep pace with most enduro bikes.

To top it off, the Slash's geometry offers a comfortable seated position, ensuring it's not a chore to ride for long stretches.

Out-of-the-saddle powerful pedal strokes create some bob, but none more than you would expect from a bike of this ilk and travel. For most climbs, you can leave the shock's climb switch open if you want, which is a testament to the Slash's climbing prowess.

Of course, there’s plenty of traction on steeper climbs and technical trails, and the weight distribution is pretty even between the wheels. I never had to shift around significantly to hunt balance or traction.

Even with its slack head tube angle, tight climbing trails weren’t a sticking point. For its category, the Slash is a competent climber, more so than you might expect from its stats on paper.

Trek Slash 9.9 X0 AXS T-Type descending performance

On the downhills is where the Slash becomes an enigma. Surprisingly, its firm shock tune and kinematics make it feel more like a confident trail bike than the hyper-capable enduro machine you might expect from its high-pivot design.

The Slash really shines on high-speed flow trails and jumps, offering great support and stability. The firm compression damping helps it power through deep compressions, drops and high-load bermed turns with impressive speed.

On the right kind of trails, it's a speed machine, maintaining momentum like a pro.

However, when it comes to tackling those rough square-edge hits, such as sharp roots and rocks, repeated braking bumps, or smaller bumps that could use a bit more sensitivity, the Slash comes unstuck. This made me a tad hesitant on more natural trails.

The firm shock setting that gives the bike its impressive support for pedalling and maintaining speed when pumping is required takes the edge off of its ability to thrive in the rough – the Slash’s natural habitat.

I believe there’s plenty of potential in the frame. However, having the RockShox Vivid’s firmest C37 compression tune on the Slash for my 75kg weight, even with the compression settings fully open, made the Trek feel as though it was thudding along rough trails, rather than floating and absorbing the bumps with finesse.

The suspension compression felt lethargic and heavy, and didn’t highlight the high pivot's biggest selling point.

However, it feels impressively agile and easy to handle, despite what the numbers suggest.

It's responsive and enabled me to manoeuvre through tight turns with ease. I could lean into corners and make precise line choices without hesitation.

It manages to stay balanced and nimble, maintaining its handling even during those high-compression moments. Plus, it’s easy to place on the trail where you want.

However, on slower-speed, flatter turns, I had to load the front wheel more than expected. This is probably because the slack head angle and short rear stays – which don't extend much without the bike sinking into its travel to even up the front and rear centres – creates a front-to-back imbalance. This wasn’t an issue through most corners, though.

Its stiff carbon wheels and handlebar, along with the firm suspension, result in a demanding ride. I certainly felt some feedback in my hands during longer descents.

The Slash is precise and nimble, but it's fatiguing and needs some authority to ride fast over rougher trails.

The Bontrager tyres aren’t a highlight either. When the trails are dry, they’re acceptable but don’t offer the most damped and controlled ride feel.

When things get slick, the rubber compound is out of its depth and makes the Slash nervous and sketchy. This isn't the bike's fault, and it outshines the tyres easily.

How does the Trek Slash 9.9 X0 AXS T-Type compare to the Devinci Chainsaw GX 12S?

While these two bikes are worlds apart in terms of price, materials and spec, they’re very similar in terms of geometry, travel and intended use. On the trail, however, they’re like chalk and cheese.

The Trek, it seems, is all about efficiency and making a high-pivot bike capable of all-day pedalling missions. The Devinci throws climbing performance out of the window but thrives on the descents.

I don’t think you can go downhill faster for cheaper than with the Devinci. However, you’re not going to want to pedal the Chainsaw around a 50km enduro loop.

The Devinci will devour whatever is in its path, where the Trek is a more fussy bike, thriving on certain trails and spitting its dummy out on others. If you’re a bike-park shedder, ripping laps and using uplifts, the Devinci will be your best friend.

If you prefer to earn your turns and find more secluded wild trails, the Trek is a smarter choice. It’s interesting to see how two very similar concepts can behave so differently.

Trek Slash 9.9 X0 AXS T-Type bottom line

I feel there’s tons of potential in the new Slash, and it may work for plenty of riders already, but the shock needs a retune to release the bike's full high-pivot potential.

I should praise Trek for its ability to minimise drivetrain friction though. What it has achieved is impressive.

The Slash 9.9 X0 AXS T-type will suit riders wanting efficient, stable and predictable handling while heading off on enduro missions.

I would take a lower-specced model though and forgo the stiff carbon wheels and integrated handlebar, for something more forgiving and practical.

Trek has given us a high-pivot bike that excels in many aspects but comes with a few compromises.

The world of high-pivot bikes is here to stay and it's bound to get even better in the future. The Slash is just a glimpse of what's to come.