Trek Slash+ 9.9 X0 Review: Ultimate Enduro Performance

The Trek Slash+ 9.9 X0 AXS T-Type is the latest evolution in Trek’s enduro lineup, pushing the boundaries of aggressive trail riding with cutting-edge technology. This long-travel, mullet-ready, carbon-framed beast blends stability, control, and cutting-edge wireless shifting into a package designed for riders who demand confidence at high speeds and capability on gnarly descents. But how does it really perform on the trails? Let’s dive in and don’t forget these essential Gear for your ride.

Pros ✅

✅ Ultra-Stable Geometry – Long, slack geo provides excellent control at speed.
✅ High-Quality OCLV Carbon Frame – Lightweight yet incredibly durable.
✅ RockShox ZEB Ultimate Fork (170mm) – Plush suspension that eats up rough terrain.
✅ RockShox Super Deluxe Ultimate Shock (170mm) – Offers incredible small-bump compliance and big-hit absorption.
✅ SRAM X0 AXS T-Type Wireless Shifting – Instantaneous, precise gear changes with no cable hassle.
✅ Mullet-Compatible – Option to run a 29/27.5 setup for added playfulness.
✅ Solid Climbing Efficiency (for an enduro bike) – The revised suspension kinematics improve pedaling performance.
✅ Long-Lasting Battery Life – The AXS system battery provides reliable performance for multiple rides before needing a recharge.

Cons ❌

❌ Expensive – Premium components come with a premium price tag.
❌ Not for Casual Riders – This is a bike designed for aggressive enduro racing, not mellow trail cruising.
❌ Weight – Slightly heavier than some competitors in its class.
❌ Overkill for Light Trails – If you aren’t hitting big terrain, you may not need this much bike.
❌ Battery Management Required – While the AXS battery lasts long, forgetting to charge it could leave you without shifting mid-ride.

Frame & Build Quality

Trek’s OCLV Mountain Carbon frame is the backbone of the Slash+ 9.9, balancing strength and weight savings. The updated geometry features a slacker head angle (63.5°) and a longer reach, making it a high-speed monster with excellent composure on steep descents.

The knock block 2.0 system is still present, preventing the fork from over-rotating while allowing more cockpit adjustability. Plus, internal frame storage is a nice bonus, letting you stash tools or snacks inside the downtube.

Suspension Performance

The RockShox ZEB Ultimate (170mm) and Super Deluxe Ultimate Shock (170mm) deliver world-class suspension performance.

Small Bump Compliance: The Super Deluxe shock absorbs chatter effortlessly, making techy trails feel smoother.
Big-Hit Performance: Whether you’re dropping into a rock garden or sending a big feature, the suspension remains composed without feeling harsh.
Support & Progression: The rear linkage provides solid mid-stroke support, preventing wallowing while giving you confidence to push harder.

This suspension setup is tuned for big, fast, aggressive riding, excelling in high-speed chunk and rowdy enduro courses.

Battery & Battery Life

One of the standout features of the Trek Slash+ 9.9 X0 AXS T-Type is its SRAM AXS T-Type wireless shifting system, which relies on a rechargeable battery.

Battery Life: The SRAM AXS battery typically lasts 20-30 hours of riding before needing a recharge, depending on shifting frequency and temperature conditions.
Charging Time: The battery takes about an hour to fully charge via USB.
Ease of Replacement: The battery is easily swappable, and carrying a spare on long rides ensures you’re never left without shifting.
Power Management: The AXS app allows you to monitor battery levels before heading out, preventing unexpected power loss.

The battery system is reliable, but riders need to make charging a habit to avoid mid-ride surprises. If you forget to charge, you can manually shift into a usable gear and ride it out. So grab yourself a Portable solar panel to take on your ride.

Climbing Performance

For a 170mm travel enduro rig, the Trek Slash+ 9.9 climbs surprisingly well. Thanks to an efficient kinematic design, it minimizes suspension bob, keeping power transfer direct and efficient.

Seated Climbs: The steep(ish) seat tube angle (77°) keeps your weight centered over the pedals, making steep technical climbs manageable.
Technical Sections: The ZEB fork stays composed, keeping the front end planted instead of wandering.
Weight Consideration: It’s not as sprightly as a dedicated trail bike, but for an enduro machine, it holds its own.

If you ride a lot of steep, technical climbs, consider switching to a lighter rear tire to improve rolling efficiency.

Descending Performance

Here’s where the Slash+ dominates. This bike was built to go fast and send big lines with confidence.

Steep & Gnarly Lines: The long wheelbase and slack head angle make it feel planted and stable at high speeds.
Cornering: The mullet-compatibility adds an extra layer of agility, making tight turns snappier when running a 27.5” rear wheel.
Jumping & Drops: With 170mm of RockShox’s best suspension, hitting gaps and big landings feels smooth and controlled.
Braking Control: With the SRAM Code RSC brakes, stopping power is never a concern, even on sustained, steep descents.

If you love sending steep, technical, and fast terrain, this bike will make you feel like a pro.

Who is This Bike For?

This bike is for aggressive enduro riders, racers, and big-mountain shredders. If you regularly ride technical terrain, fast descents, and long-travel enduro trails, the Trek Slash+ 9.9 X0 AXS T-Type is a top-tier weapon for the job.

Who Should Look Elsewhere?

If you ride mostly mellow trails or XC routes, this bike is overkill.
If you prefer lightweight climbing efficiency, a trail bike like the Trek Fuel EX might suit you better.

Final Verdict

The Trek Slash+ 9.9 X0 AXS T-Type is a full-send, no-compromise enduro machine built for riders who push limits. With premium suspension, cutting-edge AXS shifting, and a carbon frame, it’s one of the best enduro bikes on the market.

If you’re an experienced rider looking for an aggressive, high-speed, gravity-focused bike, this is a top-tier option.

Rating: 9.5/10 – Almost perfect, but with a premium price tag.

Would you ride the Trek Slash+ 9.9 X0 AXS? Drop a comment below and share your thoughts!