2023 Trek Fuel EXe 9.9 XX1 AXS E-Bike

The world of e-bikes feels like it has been in an arms race these past couple of years. New models tout larger batteries and more powerful motors. Additionally, more electronic integrations, displays, and gadgets. This has left the world of lighter e-bikes in the hands of only a few players. Today, Trek does an about-face and offers the Fuel EXe - a 40-pound e-bike that to us, represents a new wave of eMTB.

Highlights

• OCLV Carbon frame
• 29-inch wheels (mixed-wheel compatible)
• 140mm (5.5-inches) of rear-wheel travel // 150mm (5.9-inches) fork travel
• ABP suspension design
• Internal cable routing
• New TQ Motor (50Nm max torque)
• 360-watt hour battery
• 160-watt hour range extender available
• Integrated display
• Accessory mounts on the underside of the top tube
• Boost 148 rear spacing with 12mm through axle
• Measured weight (size Medium, no pedals): 40 pounds (18.14kg)
• MSRP $13,999 USD as tested ($6,499-$13,999)

From press releases to bike tests, Vital covers most of what is new in the eMTB world. We'd be lying if what we saw lately wasn't all that thrilling. When brands come to the market with a new e-bike, it has generally been one of two motors and a discussion about big batteries. Riders are needing ramps (as observed) or a gym membership to load their e-bikes on cars. With its 52-pound heft and all the gizmos, we got in our fair share of shots with the Trek Rail in our latest set of reviews. Like a Sour Patch Kid, the Waterloo brand has now given us a taste of something rather sweet.

In sitting through the media presentation, we were floored with what Trek and TQ were laying on the table. There were tremendous promises given with plenty of fancy tests showing how quiet the new TQ motor was. There was expansive testing in Moab as engineers from TQ and Trek collaborated to make a bike that was worth riding. Additionally, the new TQ HPR50 motor uses new technology in an unbelievably small package to deliver power comparable to other light e-bikes. As it turned out, our own test bike was physically delivered while we were watching the presentation.

The Motor - TQ HPR50

TQ may not be a brand that is traditionally known or discussed among the MTB crowd. The brand has been busy making equipment for space exploration and robotics applications. TQ's HPR50 motor was developed and is produced in Germany. The motor weighs in at 1850 grams and produces a max of 50 Nm/300 Watts of torque. TQ's battery weighs 1830g for the main unit which provides 360 Wh.

TQ Display

Trek integrated the TQ display into the top tube of the EXe and stuck with a minimalist design. There are four preset data screens (not customizable) that can be scrolled through by tapping on the one button below the screen. This is also how the bike is powered on and off. Power modes are changed via the small control unit on the left side of the handlebar. Power levels are displayed on the bottom of the screen with either zero (no assist) or one, two, or three bars to indicate the level of assist. Press and hold the up arrow on the controller to activate walk mode, press and hold the down arrow to turn off all assist.

The one display that we would have liked to have had, but is not an option, is an odometer or tripmeter. Riders will have to use their GPS unit or the Trek app in order to keep track of these numbers.

The Lineup

We know the price tag of our top-shelf test bike will make many readers wince. Despite being in line with the cost of many other e-bikes on the market, $14,000 has just not normalized as a price to pay for most people. However, Trek is offering the new Fuel EXe in a complete line that starts at $6,499 with the same OCLV frame and TQ drive system.

Fuel EXe 9.5 ($6,499) - RockShox 35 Gold, RockShox Deluxe Select+, Alex wheels with Bontrager hubs, Shimano Deore 6100 drivetrain with Shimano MT4100 4-piston brakes.

Fuel EXe 9.7 ($7,599) FOX Rhythm 36, FOX Performance Float X, Bontrager Line Comp 30 wheels, Shimano SLX drivetrain (XT mech), Shimano Deore 4-piston brakes.

Fuel EXe 9.8 XT ($8,699) RockShox Lyrik Select+, RockShox Deluxe Select+, Bontrager Line elite 30 wheels, Shimano XT drivetrain, and brakes.

Fuel EXe 9.8 GX AXS ($10,999) RockShox Lyrik Select+, RockShox Deluxe Select+, Bontrager Line elite 30 wheels, GX Eagle AXS drivetrain, SRAM Code R brakes.

Fuel EXe 9.9 XTR ($12,999) RockShox Lyrik Ultimate with AirWiz unit, RockShox Duper Deluxe Ultimate with AirWiz unit, Bontrager Line Pro 30 wheels, Shimano XTR drivetrain, and brakes.

Geometry

Though Trek's new e-bike carries the Fuel EX name, the geometry is adjusted quite a bit over its mountain bike counterpart. We're used to seeing this with e-bikes, typically in the form of longer chainstays. In the case of the EXe, it runs 440mm chainstays, about 3mm longer than the Fuel EX. It is the reach and head angle where things make a more dramatic departure. Trek is not offering a size ML (as in the case of the Fuel EX and Slash line) and instead going with some adjusted numbers and larger jumps between sizes. In the case of our medium test bike, we had a 452mm reach while the move to a large is 482mm. By comparison, the Fuel EX goes 440mm (M), 455mm (ML), and 470mm (L). Lastly, the Fuel EXe has a (by comparison) slacker head tube angle of 65 degrees (66 degrees on the Fuel EX).

Not reviewing these numbers prior to riding the Fuel EXe, we would have sworn it was longer out front than what the numbers say. While the reach figures are toward the shorter side of most bikes (while still falling in the norm), it was perhaps the seat angle and top tube combination that had the EXe riding a tad longer. On the trail, we wouldn't chalk this up as a negative, more the case of the numbers not telling the whole story. Regardless, here are all the numbers:

Setup

Our palms were a touch clammy as we triple-checked our measurements and cut lines on the $367 Bontrager RSL integrated stem/bar (star?) but the 820mm width was more than our body frame could utilize. After chopping it down to 770mm, we felt a touch more at home.

We took the Fuel EXe out for a few rides in its stock form before swapping over to a mixed-wheel setup to see how it may change the ride. Moving from the Bontrager Line 30 Pro wheels to a set of Hunt Trail Wide 30s offered us a bit more compliance on the trail. Additionally, the move to a 27.5-inch rear wheel lowered the EXe and made it a touch slacker.

Production builds of the 9.9 XX1 AXS build (tested) will come with integrated AirWiz units to help with the initial setup. These units sync with your phone via the SRAM AXS app to give a recommended pressure given the rider's weight. Our test bike was devoid of these units, which we were ok with given our experience with them on the Rail. We set our SuperDeluxe rear shock to 30% sag and kept the Lyrik Ultimate within the suggested air pressure parameters.

Because the EXe and the new Trek Connect App were both under embargo, we were not able to have access to the app. This meant we were limited to only the factory tunes that Trek sends out. It has been Vital's experience with most e-bikes, and in particular these lighter versions, that a little tuning can go a long way. Our go-to has typically been to bump up the lower power settings to make them more useable and keep the higher-powered settings only for shorter rides or times when that extra boost is really needed.

On The Trail

Our test bike was ridden by four different testers on a variety of terrain in the Sierra Mountains surrounding Reno, NV. The Fuel EXe saw a lot of action in a lot of various terrain, though all of it was very dry.

DH/Technical Performance/Fun Factor

The number one thing to keep in mind is that this is a Fuel. Not a Remedy or the latest Slash. When Trek created the Fuel EXe they undoubtedly went for the middle of the bell curve with rider appeal and trail performance. Our Fuel EXe handled descents just like a trail bike should. This is not a bike that "punches up" a weight class or rides with more gusto than it should. We're good with that. Trek created the Fuel EXe for riders to get out and explore more trails. Pushing the envelope too far may turn off much of the customer base this bike is going for.

On lower-angle downhills we found it to hold speed better than a full-sized e-bike but not quite as well as a comparable mountain bike. We appreciated the EXe's ability to pump terrain and eagerly loft the lips on various jumps. Undoubtedly this was a combination of both a "lighter" e-bike and the RockShox suspension working masterfully together.

Our Fuel EXe felt very much like a "29er" and we really felt the rear wheel in the corners. Because Trek has green-lit this bike to be run with a 27.5-inch rear wheel (via the Mino Link in the high position) we went for it. What it seemed to unlock was the EXe's more playful side. Rather than wanting to make arcs in corners, we could now push in and make faster changes in direction. Admittedly, this is also due to our tester's stature. Results will vary for riders in the 5'11" and up category but we will say for our crew, the smaller rear wheel was a subjective improvement in the bike's overall handling.

We did clarify with Trek about the effect the smaller wheel would have on the bike's governed 20mph motor. It was confirmed that yes, the bike would cut out below 20mph as the motor/speedometer would think there was still a 29er out back. The beauty of these lighter e-bikes is that we never felt the early cut-out nor found it detrimental.

Rear Suspension Performance

Trek's ABP and the RockShox Super Deluxe Ultimate made for a stellar combination. Initially, when the EXe was in full 29er mode, we did run the shock a tad soft, closer to 33% sag to get a bit more of an aggressive stance out of the bike. Despite running the shock a touch soft, bottom-outs were not harsh, nor even noticeable for that matter. Once in mixed-wheel mode, we put the Super Deluxe back to 30% sag to lessen pedal strikes.

Via the compression and rebound settings on the Super Deluxe, we were able to get some very distinct ride characteristics out of the Fuel EXe. By slowing things down a tad and lessening the compression damping, we got the bike to ride heavier and stay closer to the ground. Dialing in a few clicks of "rabbit" the EXe livened right up and was a boost machine. We enjoyed messing around with these settings and will give a nod to Trek and RockShox for making it easy to dial in the bike for a given trail or ride experience.

Unique Features

Our Fuel EXe came equipped with the Bontrager Integrated Tool System (BITS). This is not our first go with the setup. We first had it on our Slash test bike. This go-round though, we found things to go a bit smoother. Our tool did not loosen up after quite a...bit of use. (See what I did there?) Additionally, the tool was always easy to pull in and out of the head tube.

There is an accessory mount on the underside of the top tube. Something that is now rather common but merits noting. We appreciated having the necessities when it came time to do our battery-burner tests and found ourselves far from home.

AXS-equipped models have the ability to have the derailleur plug in and draw power from the bike's main battery. This is pretty awesome and is another step toward more integration. We could see this being a great backup feature should riders find themselves with a dead (or missing) AXS battery in the middle of a ride.

Geometry

Prior to launch, we really didn't have much information on the new Trek's geometry. We knew there was a 65-degree head angle but that was about it. To that end, our ride experience was unspoiled by pre-conceived notions based on numbers. Our medium EXe had a long feel to the front end when pedaling around but was not so spacious that we were stretched out. Our weight distribution on climbs was darn-near perfect.

While descending, the Fuel EXe gave us the sensation of a longer back end. This was part of why we opted for a smaller rear wheel for much of our testing period. Perhaps larger riders won't share this sensation but for us, it was a shared notion among three riders.

Perceived Weight

Our 40-pound test bike felt exactly like a 40-pound bike on the trail. In particular, we noticed this when getting back on our 31-pound mountain bike after riding the EXe. Conversely, we also noticed the weight differential after getting off a 48-pound e-bike. To that end, the EXe is successful in striking a balance between the worlds of mountain biking and e-biking.

TQ's HPR50 motor is brilliant.

Sprinting

TQ's HPR50 motor is brilliant. We've not felt a motor deliver such smooth, natural-feeling power as we have with the TQ system. One tester stated that with conventional e-bikes, you feel the power of the motor pulling you. With the TQ, you feel as if you are the one delivering the power. Regulating motor power is no different than regulating your own. We were never caught off-guard or left gooning on the trail when the motor kicked in.

Climbing

The Fuel EXe is a happy climber. We don't mean that in the sense of it has a motor, therefore it climbs well. We mean it in that body position and efficiency are both great. There is enough space to adjust your body on long, sustained climbs. Additionally, bearing down on the pedals and going after those more chunky and technical bits nets positive results.

In swinging between two wheel sizes, we did not notice a loss or gain in the bike's overall ability to get up and over ledges or more challenging bits of trail. With the lower bottom bracket, we did have to be mindful of pedal strikes (we had a lot) in those rocky bits. As it turns out, our desert testing ground is pretty much nothing but rocks. Go figure.

By and large, almost all of our time spent riding the Fuel EXe was in the highest power mode. We did dabble with lower settings but really just wanted the full pull to test the power and worst-case battery life. At 50 Nm of max torque, the TQ motor won't pull you up the hill like the more-common 85 Nm power plants out there. We did several back-to-back rides with the EXe and a Santa Cruz Heckler to compare the sensations.

Far from scientific and certainly affected by a few variables, we did do some timed rides with a GPS and heart rate watch. In those cases, we were able to hit the same waypoints on a climb at the same time abord the EXe in full power as we did with the Heckler on Trail mode (mid-power). The flipside was slightly more effort from our body and greater battery consumption by the TQ system. As stated earlier, we would have liked to have been able to tune the TQ power delivery and potentially get more out of the mid-power setting.

We took the Fuel EXe on two very different rides that were both targeted at draining the battery to find its range. We rode the EXe in max power for both rides and in both cases, the same tester was riding the bike. Our first ride was a steep, unrelenting climb, followed by a steep, unrelenting downhill. Once at the bottom, we went up the other side of the valley for more of the same. We rode an out-and-back trail to allow us to just bail once the motor died. In that case, we got 14.3-miles and about 3,600 feet of climbing. Our second burner ride was more indicative of a traditional ride with more undulating terrain and less punch-in-the-face climbing. In that case, we got 20.8 miles and 2,700 feet of climbing.

Once the battery hits 10%, the display will begin flashing (inducing some unwanted anxiety) and the max power output will be limited to 110 watts. The first time this happened, our tester was in the throes of scaling a dirt wall and the sudden loss of power was jarring. It was a painful ascent for that last 10% of battery but we pressed on in the name of science. The second time we hit the 10% mark, it was still jarring. Any time your drop a power level on an e-bike, it always feels like a punch. The legs and heart just aren't ready for it. Regardless, we finished off the battery just one mile from home. That last mile was the hardest. With that said, the experience is nowhere near as brutal as with a full-sized eMTB. Again, the Fuel EXe strikes a middle ground.

Build Kit

Our test bike was (surprise) Trek's top offering, the 9.9 XX1 AXS. Despite being the top-shelf build, it is actually not the lightest. That honor belongs to the 9.9 XTR ($12,999) with a claimed weight of 38.5 pounds. The heaviest EXe is the 9.5 ($6,499) at 43.94 pounds.

Fork Performance

This is not our first dance with the new Lyrik but it is our first go with it on an e-bike. We are happy to report that the eMTB version feels every bit as good as the MTB version. That distinct touch-down feel is pillow-soft and the range/ease of adjustments is fantastic.

Tire Performance

Our Fuel EXe came with the Bontrager SE5 tires front and back. For our desert conditions, they proved solid performers, perhaps a bit hard on the rubber compound. We won't lean too hard into that because June in the Sierra is very dry. Because they were already on our alternate set of wheels, we did run the Maxxis DHRII for a spell.

Wheel Performance

We've ridden the Bontrager Line 30 Pro wheels quite a few times over the years. We've always noted them to be a stiff wheel and this go-round kept that tradition and then some. The Fuel EXe chassis is quite stiff. Couple that with some stiff carbon wheels and our testers found the EXe to be rather skiddery and harsh. After swapping to the Hunt Trail Wide 30 hoops, we did get a bit more compliance.

Brake Performance

Despite the moderate travel numbers and general aim, Trek outfitted the EXe with 200mm rotors and Code RSC brakes. Slow clap. Our brakes performed quite well and we were very happy to have all that stopping power on tap.

Drivetrain Performance

We had no issues or concerns with our XX1 AXS drivetrain, no surprise there. In the motor department, the TQ HPR50 is as quiet as anything. In the workstand it does make a very small whirring sound but as soon as it hits the trail, the motor noise disappears beneath the sound of rubber on dirt and the subtle wind in our ears. There were many things we loved about the TQ motor but its silence stood out as a leading virtue.

We noticed that when starting out and pushing hard in a higher gear, there was an every-so-slight shudder sensation. Our understanding of the TQ motor is that of a one-way bearing and this feeling is possibly the system locking in. Truly, we only noticed it when pressing hard to specifically test the motor engagement. We never felt it on the trail.

Noise

In every e-bike we've tested, this is generally the area where we say the bike is quiet other than the motor knocking on the descents. With the TQ HPR50, there is no knock. It remains silent up and down the hill, much like the rest of the bike it powers. The only noise we got out of the Fuel EXe was a little headset creak from dust and hard riding. Once re-tourqed, the noise disappeared.

Overall, there was plenty to love about the build of the Fuel EXe. Any of the parts we had any subjective issues with are readily remedied by buying a lower-end model. Actually, we would have been better suited by one of the two lower models. With (relative) minor weight penalties and price tags at half the cost of our test bike, we would eagerly recommend the 9.5 or 9.7 models.

Long Term Durability

Our lead tester is four for four in having some nasty crashes aboard Trek bikes. Our Fuel EXe actually took a few hard tumbles beneath multiple testers. Aside from some cosmetic damage (that RSL bar/stem being one of them), our EXe proved to be a real trooper.

In swapping our Mino Link, we found the bearing shields to be doing their job in keeping out the dust. We will not vouch for mud and water beyond washing. The e*13 cranks took quite a few knocks and have a number of battle scars. Aside from all this rough living, the Fuel EXe isn't complaining or making any odd noises.

...the Trek Fuel EXe just elevated the eMTB game.

What's The Bottom Line?

Trek has done it. They have created a lightweight eMTB that strikes the balance of power and all-around rideability. Where other brands' lighter models lack easy battery removal, the EXe line can dump the battery in a minute. Heck, it can even be ridden without it or with just the range extender. Overall power delivery is smooth and intuitive while the range is impressive. Our personal preference may be for a more aggressive bike but there is no objectivity in that claim. We have to call it as we see it and the Trek Fuel EXe just elevated the eMTB game.

Head to Trekbikes.com to learn more

About The Tester

Brad Howell- Age: 43 // Years Riding: 28 // Height: 5'9" (1.75m) // Weight: 165-pounds (74.8kg)

Brad started mountain biking when a 2.25-inch tire was large, and despite having threads, bottom brackets sucked. Riding in the woods with friends eventually lead way to racing, trying to send it at the local gravel pits, and working in bike shops as a wrench to fix those bikes. Brad has been fortunate enough to have dug at six Rampages, attend some World Cups, work in the industry for a few years, and become friends with some of the sport's biggest talents. These days, he just likes riding his bike in the woods with friends.