Words Georgia Petrie
Images Cameron Mackenzie
RRP $19,999
Distributor Trek NZ

It’s fair to say we’ve seen a whole heap of changes within the eMTB landscape over the past few years. The last 18 months in particular have brought about the cementing of the SL (Super Light) category, and an absolute smorgasbord of full-powered options. Gone are the days of an eMTB resembling somewhat of a retro downhill bike with a motor strapped to the bottom. The wide range of battery sizes, motor options and travel means that the whole e-experience can now be more tailored than ever before.

With so much choice on the market, there’s something to be said for Goldilocks’ age-old personal tagline of “just right”. This is exactly what comes to mind when it comes to the increasingly popular SL eMTB category. Increasingly, we’re seeing more and more bikes in this class being specced with bigger batteries paired with lightweight, low-power SL motors, resulting in bigger battery range whilst maintaining a ‘not-too-heavy’ ride experience— in other words “the best of both worlds”.

The Slash+ is essentially an electrified version of Trek’s ever-popular acoustic Slash, with the high-pivot, eye-catching chassis boasting a grunty 170mm of front and rear travel, with a fork that can be up-travelled up to a whopping 190mm. No mistake made—this is a burly bike that’s right at home on the roughest of double- black trails—and, as I came to learn: the rougher and more technical the trail, the more the Slash+ thrives, all without compromising on climbing ability. By incorporating a hearty 580wH battery paired with TQ’s HPR50 motor, the Slash+ strikes a balance, enabling you to “do more”; whether it’s an extra after-work lap, a backcountry ride – or even the difference between going for a post- work spin and staying home, especially as we say goodbye to post-work daylight hours once again!

eBike Features

Although sporting the same 50Nm, 300-watt peak powered TQ-HPR50 motor as its shorter-travel Fuel EXe counterpart, a key point of difference—the defining factor of the Slash+’s place in the eMTB lineup—is it’s chunkier 580Wh battery. This stacks up well against other mid- weight contenders, punching above its weight relative to the likes of other longer-travel ~160mm options, such as Transition’s freshly released Regulator and Mondraker’s Dune, which both sport 400Wh batteries, and paired with Bosch’s grunty 55Nm, 600W peak powered SX motor. With so much choice and such subtle differences between motor and bike manufacturers, whether you’re a weekend warrior tackling technical blues or a park rat aiming to tackle every double black option in one day (and still pedal home afterward), the SL eMTB space really has expanded to cater for a wide range of rider types.

Alongside its big battery, a core outlier of the Slash+, relative to many of its SL competitors, is not only a removeable battery but the ability to swap between TQ’s 360 or 580Wh batteries, or swap in a fresh battery mid-ride. There’s also the option to purchase TQ’s 160Wh range extender, which fits snugly into the bottle cage, weighing 950g. The TQ-HPR50 is discreetly tucked away and pleasantly quiet even under load on full power mode, making the Slash+ one of the stealthiest long-travel eMTB’s I’ve ridden. The motor has three power modes and a ‘walk’ mode, rounded out with TQ’s integrated top- tube display, and two-button handlebar remote. Though the max power assist level and pedal response for each mode can be easily fine-tuned via the Trek Central and TQ apps (though I’d prefer to have one central channel for adjustment), I found the display a little unintuitive at times, and both this and the two apps almost a little tacky and clunky relative to counterparts such as Specialized’s Mission Control App, and Bosch’s eBike Flow app, both of which have undergone significant iterations and deliver a more refined and intuitive user experience. I also found the ‘walk’ button somewhat unwieldy to access and slow to kick-in, which isn’t uncommon across the wide range of eMTB brands I’ve tried and, whilst not a dealbreaker, can be rather frustrating.

Geometry and Frame Details

Make no mistake, the Slash+ is burly bike. With 170mm of front and rear travel, paired with a 63.4° head angle and 1233mm wheelbase, the Slash+ is made for steep, rough terrain—it’s fair to say that anything less is wasted upon this bike. At 77.5° the seat angle is surprisingly steep for a bike of such travel, making for a comfortable all-day climber that’s planted on steep ascents, with a particularly upright seating position making light work of long stints in the saddle – and making you second guess that you’re basically riding a mini downhill bike uphill.

This concoction of generous geometry has created a bike that descends exceptionally well with minimal compromise on climbing ability—the point of instability more or less doesn’t exist on the Slash+, with the bike instead asking for more if tackling anything below a double black technical or jump trail. Paired with a reach of 479mm, the Slash+ does feel generous relative to other SL offerings, with plenty of room to move around on the bike, whilst the 29” front and 27.5” mullet wheel size setup creates a sense of nimbleness oftentimes lost in eMTB experiences. Overall, the bike was exceptionally well-rounded, and one of the most versatile bikes I’d ridden in a long time. For how capably it descends, it almost seems wrong to climb with such comfort!

When it comes to nitty gritty frame details, the Slash+ has a plethora of thoughtful details. The integrated chainstay protector isn’t here to faff around—this thing is chunky and robust, and it means business when it comes to limiting chain slap, which is often a dinky afterthought on so many stock eMTB’s. On the Slash+, however, it’s a welcome addition—especially given the rough terrain that the bike is best suited to. The rear fender is also a nice touch—so often I’ve ruined frames with small-yet-mighty stones that work their way in between the rear wheel and chainstay, and this does a nice job of helping minimise this as well as keep mud at bay. There’s also a custom, Trek-specific chain guide which mounts directly to the motor housing—given my experience with zero chain drops, I’d say this is a well-executed addition. I found the charging port location a little odd to work with, having been so used to side-mounted ports, and often found myself having to really yank the charging cable hard to remove it once charged, which sometimes resulted in inadvertently smacking it on the underside of the top tube—oops. Having said that, this location makes sense when considering the bottle mounted TQ range extender, which fits snugly in this space when attached.

Ride Performance

For a bike with a 170mm fork up front, the Slash+ is an exceptionally comfortable climber, sitting high in the travel with a balanced centre of gravity. Not once did I find myself fighting to keep the front wheel on the ground, which is impressive considering the bike’s relatively slack head angle. It navigated tight switchbacks with surprising ease despite a long wheelbase—there was many an occasion where I was glad to have a mullet configuration, as it gave an otherwise cumbersome bike the ability to navigate tight, technical ascents. Traction isn’t an issue—in fact, this was one of the most planted bikes I’d climbed on, with a rear wheel that’s never fighting for grip. The Rockshox Vivid Air shock behaved itself well with minimal ‘bob’. Whilst the Rockshox AXS Reverb is a welcome addition on any eMTB—anybody who’s had to complete any mechanical dropper post maintenance on an eMTB will attest to how much of a headache it is—the standover on this bike is low at 77.6mm for our 17.5” sized test bike and, when paired with a 170mm dropper post, it leaves a little more seatpost exposed than desired, especially for longer limbed riders like myself!

As I’ve found with other TQ-HPR50 equipped bikes I’ve had the opportunity to ride, the power delivery is akin to a “pat on the back”—someone giving you a little push of encouragement climbing up the hill. Let’s be real, at 20.8kg, whilst the bike does fall into the SL eMTB category, the Slash+ is on the chunky side relative to the power that the motor can produce. There were numerous times where I found myself wanting more from the motor—I was surprised at the cadence level required to maintain optimal power delivery, particularly on road climbs. On a number of occasions I felt a twinge of surprise when the motor appeared to hit the point of peak power delivery—“is that it?!”, I asked myself, as I kept getting dropped by my fellow SL eMTB riding crew.

This is a great segway into battery chat; I’ve been fortunate enough to have a tasting platter of SL eMTB’s so far, and when the Slash+ showed up in my garage, I had range curiosity! My conclusion was one of uncertainty—whilst it initially seemed great to have the reassurance of a bigger battery, what I often found was that the weight of the bike required me to run the motor on a higher-than- usual mode, and I often found myself drawing battery at such a rate that it cancelled out the supposed gains of increased Wh. My experience with this motor also matched that of the Fuel EXe, in so far as the way the power is delivered seemed to draw battery at a greater rate than other SL counterparts, such as Shimano’s EP8 RS and Specialized’s SL 1.2 motor—this was even more apparent on the Slash+ with the additional bike weight the motor had to carry.

However, I was still able to tackle a solid 2.5hr long loop with 15% remaining and at no point was I unable to make it up any of Christchurch’s steepest Victoria Park fire roads—just don’t expect to be setting any Strava e-QOM’s! It should also be noted that the TQ motor continues to maintain its reputation of being without a doubt the quietest motor I’ve experienced, providing power almost silently. While it doesn’t bother me, I’m well aware that motor noise is a sensitive issue for some eMTB buyers, making this great news for those who prefer not to hear their bike humming as they ride.

The 9.9 AXS T-Type build is specced with, you guessed it, SRAM’s X0 AXS drivetrain. This performed reliably and with crisp efficiency throughout the duration of my testing, though I did notice that the drivetrain quickly became noisy unless spotlessly cleaned after almost every ride. Whilst Christchurch will provide you with an overwhelmingly dry riding experience and taking a rain jacket “just in case” is uncommon, this does equate to A LOT of dust, which for this bike means constant maintenance to ensure the drivetrain remains smooth under pedal load, and drag-free. I think we easily doubled our chain lube consumption for the duration of testing to try and avoid any ear-twitchingly uncomfortable grinding drivetrain noise. The other interesting characteristic of this particular X0 AXS drivetrain is that it’s powered by the primary battery—the plus side to this is that you don’t need to worry about swapping or monitoring batteries (let’s face it—we’ve all been “that guy” at the trail asking around for spares…) as long as the bike is charged. The flip side to this is that if you happen to find yourself in a sticky situation, or running the battery down to it’s last drop of juice, you’ll lose the ability to shift gears because once that primary battery dies, that’s your drivetrain power source gone.

Descending on the Slash+ is a dream—this has to be one of my favorite eMTB’s I’ve taken down the rocky steeps of Christchurch, and I’ve been fortunate enough to throw a few into the dustbowl! The 170mm RockShox ZEB ultimate was an absolute delight—it took minimal time to setup and performed excellently in the chunkiest of rock gardens, and was incredibly stout without feeling too stiff. This made for a comfortable descending experience that excelled on rough terrain; the more technical the trail, the more the bike ate up whatever was underneath it. The mullet setup gave the bike a touch of nimbleness that balanced out its long wheelbase and slack head angle, creating a far more agile ride than I’d ever have imagined for a 20kg, 170mmm eMTB. Whilst the bike is certainly planted and hugs the ground—and therefore tracks exceptionally well—it was still surprisingly easy to jump and move around underneath me. I was also wow’ed with the performance of the RockShox Vivid Ultimate air shock. I’ve tried a range of different shocks in SL eMTB’s and am usually committed to the coil shock cause on my long travel bikes; however, the suppleness of the Vivid and its small bump sensitivity was so confidence-instilling that it’s got me thinking I may re-explore an air shock on my next bike build. Like the Zeb, the Vivid was a once-and-done setup for me, and it provided supple comfort over big holes without the sinking “Lay-Z-Boy” feeling you can sometimes get from bigger air shocks—it sat high in travel, even through the burliest terrain. The short chainstays are also a welcome addition.

This bike eats double black trails for breakfast, and technical blues are a great complementary snack. Make no mistake—this is a BIG bike, and if not pushed hard enough or ridden on terrain that doesn’t suit it—think flow blue trails—it may tend to feel cumbersome and even stiff at times, particularly due to the suspension being on the less active side. For this reason, it’s definitely best suited to a rider who likes to push a trail bike to its limits. For the terrain I often ride, this platform was ideal; for my first foray into the high-pivot world, I was left wanting more as it created an incredibly stable ride that seemed to make the usual bone-rattling, small bumpy sections feel like I was floating on a magic carpet. When combined with the added weight of a motor and big battery, the bike feels incredibly balanced and, as is so often the case on SL eMTBs, I felt more stable—and, as a result, much quicker—on wide-open, fast, chunky descents than on my acoustic bike. People often think an eMTB is reserved for heavy, cumbersome ride feels, but I believe that with the right platform and weight balance, the ride experience is arguably more comfortable. Trek have done an exceptional job designing a platform that’s so stable and confidence-inspiring yet still maintains some degree of nimbleness and maneuverability.

When it comes to contact points, I must admit I was a little skeptical when I noticed the SRAM Maven Silver brakes—a sore point with many stock eMTB builds is underpowered brakes, and constantly battling to control speed is taxing and creates an unnecessarily arduous ride experience, even if they’re great descenders otherwise. I was pleased to discover that this wasn’t a concern with the 4-piston Maven Silvers—when paired with hearty 200mm rotors, I didn’t once feel like the brakes were under-gunned and didn’t suffer from the sore hands I’ve so often had with other SL eMTB’s in the past. This was complemented by the levers being on the larger size with plenty of adjustability—a particularly important factor for smaller hands—and gradual modulation that allowed for increased control, which is well-suited for the steeper terrain that the Slash+ excels on. I was also pleased to report nothing but silence from these brakes, even in dry, dusty summer conditions—a welcome change from SRAM brakes of years gone by!

As was the case with the Fuel EXe, the Bontrager contact points left a little to be desired—the grips were thick, uncomfortable and incredibly slippery when wet, which I unfortunately discovered was compounded by the fact they take a long time to absorb once wet, due to their ribbed nature. Another change I’d be making immediately is the stock Bontrager SE5 Team Issue TLR tyre. Whilst a grunty 2.5” tyre such as this is a logical choice for a bike of this travel and, in theory, should be well suited to the terrain, the compound lacked grip and was a little more skatey on Victoria Park’s loose clay than was comfortable. A few “oh s***!!” moments were had as grip limits were hit a little earlier than preferred. I’m also fine compromising weight and rolling resistance to optimize grip, but this was a little on the slow side with next to no grip gains, and something I’d swap out pretty quickly for a softer compound option. I’m also pleased to say that throughout the Slash+’s tenure in our garage, not a single chain was dropped, and I didn’t experience any significant chain slap, even on the roughest of rock gardens and rooty sections.

Summary

The Slash+ is a heavy-hitting descender that delivers excellent ride performance when pointed down the most burly, technical trails in your backyard. With a bigger range than its younger brother, the Fuel EXe—but without the “chonk” of its bigger brother, the Rail—the Slash+ is Trek’s quietly capable middle child. Equipped with a quiet, subtle motor that’s so stealthily integrated that even the most eagle-eyed eMTB riders will need to look twice to see it, the Slash+ represents a well-rounded eMTB that has your back no matter what it’s pointed down. While you’re not going to lead any eMTB climbing segments on Strava, you will be making gains in your ability to ride more and squeeze in “one last lap”—even when the post-work clock is up against you. I have to agree with Goldilocks, there’s something to be said for things being “just right”, and the Slash+ might just epitomize that saying perfectly.