2025 Trek Slash+ on review – A new enduro eMTB with TQ motor and big battery

Trek unveil a new “light” e-mountain bike. The Trek Slash+ features a lightweight TQ motor and a newly-developed 580 Wh battery. As the name suggests, it’s the electronic counterpart to Trek’s analogue enduro bruiser, the Slash. The flagship model weighs in at 20.9 kg and retails at an eye-watering €11,999. Here’s our first review for you!

American bike colossus Trek electrified the analogue Slash, giving birth to the Trek Slash+. It combines the key features of the Slash enduro bike – mullet wheel setup and 170 mm of travel front and rear – with the light system weight, the quiet support of the TQ HPR50 motor and a big battery. With the new 580 Wh battery, the Slash+ is ready for long trail adventures. For comparison’s sake, the TQ HPR50 motor was previously only available with a small 360 Wh battery. Despite its light support drive, the bike isn’t exactly a featherweight at over 20 kg, evoking comparisons with the new YT Decoy SN, which also tips the scales at over 20 kg but comes equipped with a FAZUA motor. Trek’s new eMTB costs a hefty € 11,999 in the tested configuration, with entry-level models retailing from € 7,999. A comparable TQ-equipped bike would be the Simplon Rapcon Pmax TQ, which scored top marks in our big 2023 e-bike group test – can the new Trek Slash+ deliver similarly impressive results?

The new 2025 Trek Slash+ in detail: High pivot and removable battery

Trek offer the new Slash+ in two sleek paint finishes. However, the bike’s standout feature is undoubtedly the high-pivot rear suspension design, a concept rarely seen on e-bikes, which promises to deliver a smooth ride. In a nutshell, high pivot idler systems position the main pivot much higher above the chainring, which allows the rear axle (and thus the wheel) to rotate up in an arc with a rearward axle path, meaning that when the wheel contacts an obstacle, it rotates upwards and backwards, instead of upwards and forwards like most low pivot suspension systems. However, as the axle moves backwards, the distance to the top of the chainring grows longer, which can cause unwanted pedal kickback. The best way to counteract this is to use a chain idler pulley at or near to the high pivot, which maintains an almost constant distance from the rear axle – this is also what gives high pivot bikes their distinctive look.

The semi-integrated cable routing through the frame ensures relatively easy servicing and makes it easier to adjust the cockpit compared to fully integrated setups with cables routed through the headset. Although the cables reappear at the transition between the main frame and swingarm, they’re securely and neatly clamped. An extensive chainstay protector further ensures a quiet ride. The Trek Slash+ features a bottle cage mount on the downtube and a tool mount at the bottom of the top tube, allowing you to carry a water bottle and tool directly on your bike. Unlike its analogue sibling, the Slash+ doesn’t have a storage compartment in the downtube, which is taken up by the battery. However, the flagship model comes standard with an integrated tool in the headtube. There’s also a big fender at the rear end, which keeps mud away from the shock and your calves.

The TQ HPR50 motor system of the 2025 Trek Slash+

The compact TQ HPR50 motor is discreetly housed behind the crankset and chainring, and is barely noticeable apart from the cooling fins and small blue TQ logo on the non-drivetrain side. Integrated into the top tube is a black-and-white display with a button, which provides several riding data and can be controlled via a two-button remote on the handlebars. This remote allows you to toggle between the three support modes and activate walk assist. For those seeking additional metrics and tracking features, the Trek Central app is a must-have, offering handy extras like a range map.

The 580 Wh battery, which makes its debut on the Trek Slash+, is also developed by TQ. Integrated into the downtube, it can be easily removed by undoing two bolts and sliding it out towards the motor, a system familiar from the Trek Fuel EXe. For shorter rides, you can swap it for the smaller 360 Wh battery, which can be installed using an adapter, and saves around 800 g. If you need more range, the battery can be expanded with the optional 160 Wh range extender, though this means sacrificing a bottle cage and shelling out an additional € 550. The battery can be charged using the charging port on the downtube, which is conveniently placed just above the bottle cage.

The two different spec variants of the 2025 Trek Slash+

The Trek Slash+ comes in two versions. The Trek Slash+ 9.9 is the flagship model, and was designed to leave no wish unfulfilled. The new RockShox ZEB Ultimate fork with 170 mm of travel and Charger 3.1 cartridge offers countless adjustment options and delivers a tremendous performance on the trail. The RockShox Vivid Ultimate shock provides equally extensive adjustability and is said to match the responsiveness of a coil shock. The Bontrager Line Pro 30 carbon wheelset aims to keep the weight down and is paired with Bontrager SE6 tires in the front and SE5 tires in the rear for protection.

Tuning Tip: Upgrade the tires with a more robust casing for enhanced puncture and impact protection.

The electronic SRAM X0 AXS drivetrain ensures precise, quick gear shifts, even under load. It draws its power directly from the main battery, so there’s no need to worry about charging an additional AXS battery. Even when the bike battery is empty, it should still provide enough capacity for about 300 shifts. The electronic Reverb AXS dropper post offers 170 mm in size L, and ensures a tidycockpit. The SRAM Maven Silver brakes deliver extremely powerful deceleration. The cockpit, featuring Bontrager handlebars and stem, is combined with the Bontrager BITS Steerer Tube Tool, so you always have a multitool at hand. With this setup, the bike weighs in at 20.9 kg, retailing at an eye-watering €11,999.

The Trek Slash+ 9.7 offer a solid spec at a significantly lower price, retailing at € 7,999. However, you’ll have to compromise a bit on the suspension. The 170 mm FOX 38 Rhythm fork relies on a simple GRIP damper, which only offers limited adjustment options, restricting fine-tuning and falling short in trail performance. Likewise, the Fox Performance Float X shock lacks adjustability. The Bontrager Line Comp 30 aluminum wheels are designed for stability and durability on demanding trails.

The Shimano XT/SLX drivetrain is paired with Ethirteen e-spec Plus cranks, ensuring reliable performance and a long service life. With a cable-operated drivetrain, you’ll never have to worry about running out of battery. The Shimano Deore 4-piston brakes may lack tool-free reach adjustment, but still deliver reliable stopping power. The Bontrager dropper post provides a flexible seating position and freedom of movement with 170 mm of travel in size L. At € 7,999, this version is 4 grand cheaper than the flagship model, and also slightly lighter at 20.4 kg.

The geometry of the new 2025 Trek Slash+

The geometry of the electric Trek Slash+ is almost identical to that of the analog Slash. The only difference is the lack of the ML size, meaning that it’s available in four sizes, S to XL. Just like its analog sibling, it offers the option to adjust the head angle by +/- 1 degree using headset cups for fine-tuning the geometry. Additionally, there’s a flip chip on the shock mount, which allows you to increase progression, which comes in handy if you want to use a coil shock or have to handle particularly hard impacts.

The head angle in the default position is a slack 63.5º, while the seat angle measures around 77º degrees. Furthermore, the Slash+ features size-specific chainstay lengths to ensure optimal balance across all sizes.

Size	S	M	L	XL
Reach	430.0 mm	448.9 mm	478.9 mm	518.9 mm
Stack	596.7 mm	630.7 mm	639.6 mm	657.5 mm
Chainstay	434 mm	440 mm	440 mm	445 mm
BB Drop	10 mm	27 mm	27 mm	27 mm
Seat tube	390 mm	400 mm	435 mm	470 mm
Head angle	63.5°	63.4°	63.4°	63.4°
Seat angle	77.6°	77.5°	77.2°	76.7°
Top tube	561.1 mm	588.8 mm	624.5 mm	669.3 mm
Head tube	110 mm	110 mm	120 mm	140 mm
Wheelbase	1204.6 mm	1233.1 mm	1267.5 mm	1316.5 mm

The new 2025 Trek Slash+ on review

After testing the analogue Trek Slash in Whistler and the Canadian backcountry, we took the electric Trek Slash+ to the Dolomites around Alta Badia. This region offers everything from steep, technical climbs to challenging descents and fast, loamy trails – the ideal setting for putting a 170 mm eMTB through the wringer.

When it comes to climbing, the Trek Slash+ isn’t a rocket compared to other full-power or even light eMTBs, but it has its own set of advantages. The TQ HPR50 motor delivers its 50 Nm of torque very naturally, with power building smoothly and the motor engaging and disengaging discreetly. As soon as you ease off the pedals, the motor stops supporting , and doesn’t give you the delayed push typical of many e-bikes. This results in a ride experience that feels both natural and powerful – like having a bowl of steroid flakes with an energy drink for breakfast. The natural feel is further enhanced by the motor’s incredibly quiet operation. Even at high cadence, there’s no strained whirring sound, and on descents, you won’t hear a metallic rattling noise either. When riding in a group with analogue bikes, you won’t stand out – neither because of the noise nor with a 25 km/h uphill pace.

The riding position on the Trek Slash+ feels very centred – not too far back but not overly aggressive or front-heavy either. Even on steep climbs, the front wheel remains planted on the ground, while the rear wheel generates tons of traction. The high-pivot rear suspension bobs marginally when pedalling, but in return, the rear wheel stays firmly glued to the ground. On smoother fire road climbs, reaching for the lockout lever on the Vivid Air shock is worthwhile. While the 50 Nm TQ motor won’t shuttle you to the trailhead at full pelt, it promotes a steady, reliable ascent. The 580 Wh battery is more than capable of handling longer rides with significant elevation gain, even if you frequently use the highest support mode. Adding the 160 Wh range extender boosts the total capacity to a remarkable 740 Wh, making epic full-day tours in medium support mode totally achievable.

When the trail finally points downhill, the Trek Slash+ puts you in a well-integrated riding position, making you feel at ease from the get go with its intuitive handling. When the suspension compresses, the rearward axle path typical of high-pivot bikes is barely noticeable, and the Slash+ always remains predictable. Compared to other bikes with high-pivot suspension, the elongation of the wheelbase when the suspension compresses is significantly less pronounced, even when you reach deep into the suspension travel. The suspension offers excellent support for popping off edges and jumps, while still forgiving botched landings.

In rough terrain, the Trek Slash+ impresses with excellent stability, while the low centre of gravity combined with the well-tuned rear suspension delivers a confident, secure ride. The high front end prevents dreaded OTB moments , while the SRAM Maven Silver brakes offer powerful and reliable deceleration. On tight, technical trails with hairpin switchbacks, the Slash+ requires significant input to navigate smoothly. This is where the relatively high system weight of nearly 21 kg, combined with the modest assistance becomes evident.

Who should take a closer look at the 2025 Trek Slash+ ?

Trek target the Slash+ at performance-oriented e-bikers who want to go full blast on descents. The Slash+ excels on fast, rough terrain, inspiring huge amounts of confidence in the process. However, don’t expect a shuttle service on the climbs. While the Slash+ is steady and enduring uphill, it’s not particularly fast and requires plenty of pedal input. Riders transitioning from full-power e-bikes might find the motor a bit weak, but those used to pedalling enduro bikes uphill will appreciate the welcome assistance.

Our conclusions about the new 2025 Trek Slash+

The Trek Slash+ impresses with outstanding downhill performance, intuitive handling, and its quiet TQ HPR50 motor. Surprisingly, the Slash+ is more affordable than its analogue counterpart, which boasts nearly-identical specs – a compelling argument to finally switch to an e-bike ;). The Slash+ retains all the positive traits, like the excellent stability, and adds a gentle boost uphill. However, the focus remains firmly on descending, which is where it truly shines.

For more info, visit trekbikes.com

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Words: Julian Schwede Photos: Peter Walker