Best mountain e-bike ‘Trek’s Fuel EX-e’
Light, discreet and quiet with a better chassis, the new X-E proves that not many e-bikes can be better.
Takeaway: Motor or no motor, the Fuel EX-E is one of the best mountain bikes on the market right now.
All new EX carbon frame with 140mm rear travel and 150mm fork
Small and light (1850 g) TQ HPR50 with a maximum torque of 50Nm
360Wh in-frame battery. Optional piggyback 160Wh range extender
A claimed ride range of 2-5 hours from the in-frame battery
The six models range in price from $6,500 to $14,000
Weight: 40.9 lbs. (Medium, 9.9 XX1 AXS)
Price: $14,000 (9.9 XX1 AXS)
Trek kicks off the mountain bike’s biggest week in cycling with the introduction of their latest e-mountain bike: the Fuel EX-E. While the typical e-bike story is about more power, battery and range, the EX-e falls into the intriguing e-lite category where the story is less.
The EX-e is light, much lighter than a full-power e-bike—10 or so pounds lighter—because it uses a less powerful motor that requires a smaller battery. That makes it appealing to riders who want an e-bike but want the feel and handling of an underpowered e-bike. It should interest even lighter and less powerful riders riding a 50-pound eMTB. As I found out, being less energetic doesn’t mean less fun. The EX-e proves that the old principle of less is more works for e-bikes too.
Trek Fuel EX-e Ride Impressions
Most of the e-bikes I ride are motorised versions of the brand’s existing unpowered frame platform, which there’s a better chance than I’ve already ridden. However, with this New Fuel EX-e, Trek flipped the script on me as the powered version came first.
With the Fuel EX-e, Trek debuts an all-new frame platform that I’ve never ridden before, which is likely to be the next version of Trek’s Fuel EX trail bike (in an unpowered version). Plus, the EX-e uses an all-new TQ motor (which is new to me) and a 2023 RockShox Lyrik fork and Super Deluxe Ultimate shock (which I spent minimal time with).
Our review e-bike was the $14,000 Fuel EX-e 9.9 XX1 AXS
My test bike was the most expensive model: the $14,000 9.9 XX1 AXS in Baja Yellow. Parts were as you would expect for this expensive, flawless bike. I noticed that the RockShox Reverb AXS dropper in this post seemed smoother and less sticky than the other examples in this post that I tried, probably due to some running changes on the assembly line. The Bontrager SE5 Team Issue tires are the best Bontrager trail tires I’ve ridden, and the company has a rubber compound that allows them to compete with the best on the market. Also impressive are the 2023 RockShox components which are a step forward for the brand in smoothness and silent operation.
One thing my bike doesn’t have are Trek’s AirWiz suspension pressure sensors in the fork and shock, or the Quark TireWiz tire pressure sensors in the wheels. These were a stock feature on the model I tested, but Trek’s PR team decided to remove them from my review bike after issues I had with the sensors on the rail test bike in October. Riders who order the brand new EX-e via Trek’s Project One customization software have the choice to get rid of the sensors.
Although much of this bike was new to me, the Fuel EX-E was such a harmonious package that I quickly became comfortable with it and it wasn’t long before I fell in love with this bike. In fact, I’m going to declare it one of the best mountain bikes I’ve ridden recently – powered or unpowered. I can’t wait for the unpowered version of this frame to drop because I think it will kick ass.
Everything makes this bike great, but I’ll start with the frame. The chassis has a modern fit and balanced handling that allows the rider to comfortably climb and run on descents, yet it’s still compliant at mid-speed and flat trails. There’s nothing particularly unique or different about the EX-e’s geometry numbers, which I think is the point: it finds a balance that works well on many types of climbs and flavours of descent without ignoring that some trails are flat. If anything, it’s snappier and livelier—I don’t think I’ve ever said that about an e-mountain bike—than an average 140/150mm bike, and I legitimately forget I’m on an e-bike at times. .
I sometimes forget I’m on an e-bike because the motor is so quiet and refined. I couldn’t hear myself breathing on climbs, and it was smooth enough that there were no vibrations or buzzing to feel in the frame. In addition, it is completely free of clunking and lashing.
It’s the most natural motor I’ve ridden yet, meaning it puts out power in an almost human way. It’s so fast that there’s no lag when you start and stop pedalling; Motor energy flows in and out. It legitimately feels like you’re having a really good day when you pedal this bike. Even in the highest assist mode, I felt less surge and push from this motor than I’ve experienced from any other e-bike motor system.
The EX-e’s motor feels exceptionally well-tuned, and the feel is refined, even overshadowing the spec’s best motors. Some of this smoothness is due to the low torque of the TQ. By keeping the system quiet, the bike tricks the brain a bit – quieter is perceived smoother. But riding the EX-e was such a pleasant experience that I never missed the extra boost of a “full power” e-bike.
The new hydraulic bottom-out control on the RockShox shock was great and gave excellent control
I think this e-lite mountain bike can give a great experience to many riders, even the committed e-bike riders. Yes, it’s not going to throw you up the climbs like a full-powered e-bike. Yes, I’d only want more range if the EX-e was a lot of fun to ride—but there’s enough power and range here to offer some substantial assistance, yet the bike remains nimble and doesn’t punish the upper body. descents. It’s an e-bike experience that doesn’t overwhelm the mountain bike experience. The experience of transitioning from a mountain bike to a full-powered e-bike can be overwhelming and jarring.
Full-powered e-bikes are a lot: plenty of power and plenty of weight. Many riders are comfortable with their full-powered e-bikes and are perfectly happy. But if you’ve tried a full-powered e-bike and thought it was a bit much, the EX-e is a revelation.
Based on Strava, even with the help of the EX-e, I was still slower on the climbs and descents than the fast pro riders in my town. I haven’t been as fast as my best unassisted times since I was in my best riding shape. But I can ride faster and with less effort (at my current weight and fitness) compared to an unassisted bike. It reduced—but didn’t eliminate—pain and significantly increased fun in a quiet, smooth, and easy-to-ride package. This to me is the hallmark of a fabulous bike.
The motor is small and discrete.
Trek Fuel EX-e TQ HPR50 motor
For the brand new EX-e motor, Trek grew to become a brand new supplier: TQ Group. Like Bosch, Brose and Mahale, TQ’s e-bike department is a small part of a big and numerous organisation with giant expertise in electronics. Although they don’t have the recognition of its competitors, this isn’t TQ’s first foray into e-bike motors: the Flyon motor used for some high bike models is a TQ product. While the Flyon is notable for its massive 120 Nm of torque, the HPR50 tops out at 50Nm (300 watts of peak assistance), adding the Fuel EX-e to the growing elite category of mountain bikes. Other e-lite trail bikes include Specialized’s Levo SL and Orbia’s Rise.
With about half the peak torque, these e-lite bikes don’t have the full thrust of a full-powered e-MTB. But less powerful motors are smaller and lighter, and they draw less juice, so bikes can use smaller and lighter batteries. And it really is why this EX-e is without problems 10 kilos lighter than a similar full-electricity e-bike. For example, the full-strength Trek Rail I reviewed last October weighed 51.3lb. With similar construction this EX-e weighs 40.9 pounds.
Due to its architecture the HPR50 is a light (1830 g) and small e-bike motor. A “harmonic pin ring” system allows for a concentric profile with no belts and fewer gears, packaging the entire unit into a shell that looks like a standard bottom bracket oversize than a typical e-bike motor. Rather than explaining the design, the hypnotic animation provided by TQ below explains it well.
Another figure I’d like to highlight is TQ’s claimed “135mm Q-Factor.” While this is true, it’s the Q-factor of a motor without cranks that, last time I checked, is hard to pedal. After installing my test bike’s e*thirteen e*spec race carbon cranks, I measured an approximate 195mm Q-factor, which is slightly wider than the Shimano EP8 motor’s 177mm.
The Trek Fuel EX-e bike TQ HPR50 Motor Noise
According to Trek’s launch materials, they spent a lot of time analysing and quantifying e-bike motor noise. And while I don’t currently consider any mid-drive e-bike motors to be loud, they all make a noticeable—and not particularly pleasant—noise. When measured in an anechoic chamber, Trek claims their motor’s tonality is four to five times lower than other e-bikes across the cadence speed range, registering as “less perceptible”.
After many hours riding the EX-e, I agree that barely perceptible is an apt way to describe the motor’s noise. It’s so quiet that it barely registers (and hides most of the time) tire noise and breathing. And not only is it quieter, the sound you can hear is a low pitch, more like a cat’s happy purr than the high pitch of most e-bike motors.
The HPR50 motor is so quiet that I can ride the EX-e in a crowd without others knowing I’m on an e-bike. If they didn’t get a good look at the bike from the non-drive side or see the discrete handlebar remote (which I tried to cover with my hand as much as possible), they assumed it was an unassisted bike. To make it even more stealthy, I covered the top tube display with electrical tape to hide it, covered the top tube logo with stickers, and rode trails closed to e-bikes. Of course, I can’t suggest you do the same, but no one I rode with gave me or the bike a second glance.
Trek Fuel EX-e battery and range
The EX-e has a 360 Wh internal battery, which according to Trek is enough for “two to five hours” of riding. While frustratingly vague, this is accurate as many factors influence battery range. Riding in “Mid” assist mode, I did a 25-mile ride with about 2500 feet of climbing. The ride took two hours and 40 minutes with less than 30 percent battery left, so I think the two to five hour estimate is accurate.
If you want more range (or worry about less range), the EX-e offers a couple of options. A 160Wh piggyback battery ($660, 900g weight) that fits into the bottle cage. You lose the ability to put a water bottle on the bike, but it provides 40 percent more range. One clever thing about this range extender is that you can charge both the bike’s in-frame battery through the charge port on the extender. Another option is to purchase a second in-frame battery ($750). You can easily remove the in-frame battery from the frame, so hot swaps are possible on the trail if you’re willing to carry a spare 1835g battery in your pack.
The claimed charge time for the 360Wh battery is a relatively short two hours, while the 160Wh piggyback charges in one hour.
The display is well protected, provides valuable information and is easy to cover with electrical tape.
Trek Fuel EX-e display, faraway and apps
The EX-e features a two-inch OLED flush with four data lines mounted on the top tube and the system’s on/off switch. The remaining charge graphic and assist mode indicator are always on and you can scroll through four data screens. More helpful are the ones that display remaining battery charge as a percentage and estimated ride time remaining, and remaining range in miles and estimated ride time remaining. Other data screens show rider and bike power and speed. Additionally, the TQ system broadcasts information over the ANT+ channel, so you can also see information from compatible GPS cycling computers.
The TQ handlebar remote is very discrete. Use it to select one of the three assist modes (Eco, Mid, High) to disable all assist or activate walk mode.
Riders can access more information and settings through the new Trek Central app for iOS and Android. The app can customise all three assistive modes. However, assist-system firmware updates must be done through a Trek dealer.
All help modes may be tuned withinside the Trek Central app. Courtesy
The central app also offers ride tracking/recording (with automatic export to Strava and Commute) and navigation with remaining battery charge at the end of the trip. It also has a range cloud that shows how far you can ride if you want to do a round trip and how far you can ride on a full charge.
The central app also provides suspension and tire pressure setup information based on rider weight and recommended suspension damping settings. If your bike has Trek’s TireWiz or AirWiz electronic pressure sensors, the app connects to those devices as well.
The EX-e uses Trek’s familiar ABP suspension.
Trek Fuel EX-e frame details
The EX-e is the debut of Trek’s all-new carbon frame platform. Although the e-bike version is the first to be launched, I bet an unassisted version of the same frame will be coming soon. It has a full range of models with a 140mm rear travel mid-travel trail frame and 150mm forks (it can take up to a 160mm fork). Additionally, Trek seems to be going in a new styling direction with the EX-e, as the frame shapes and graphics seem more subtly crisp than previous mountain bikes.
The rear suspension is Trek’s familiar ABP (Active Braking Pivot) design. The ABP is a single pivot system with a floating brake arm that allows nerds to fine-tune the bike’s anti-squat (pedalling) and anti-rise (braking) characteristics using a more traditional single-pivot design. Trek says the Kinetic works with either air or coil shocks, and says all coil shocks from Fox and RockShox are compatible with the EX-e.
All frame sizes fit a 20-ounce water bottle inside the front triangle, and there’s even a cargo mount under the top tube. The hoses and housing move internally (of course), but this frame doesn’t use Trek’s knock block system to limit bar rotation. This was sacrificed to make room for the in-frame display.
Geometry table! Courtesy
The EX-e’s geometry is quite common for a contemporary-day 140/150mm journey path bike. Highlights are two geometry positions (a chip in the rocker link gives a 64.7- or 65.2-degree head angle/76.7- or 77.2-degree effective seat tube angle) and chainstays that measure around 440mm.
While the entire bikes come with 29-inch wheels, Trek says the bike will be compatible with a 27.5″ rear wheel.
Trek recommends using a higher geometry position with an undersized wheel. However, it warns that “a small wheel circumference affects the accuracy of tempo readings and can not be adjusted.”
Trek Fuel EX-e models
There are six EX-e models—starting with the $6,500 Fuel EX-e 9.5 and topping out with the $14,000 EX-e 9.9 XX1 AXS. All use the same carbon frame, TQ motor and 360Wh battery, but the rest of the build varies according to price. Trek has provided complete bike weights for the line, which I’ve pasted below, and you’ll also find build highlights. Complete component package details are available on Trek’s website.
Fuel EX-e build highlights
Notably, the most expensive EXe is not the lightest bike in the range. The $13,000 Shimano XTR build and $8,700 and $9,200 Shimano XT bikes weigh lighter than the range-topping $14,000 SRAM XX1 AXS-equipped model. Also, the less expensive 9.5 model (remember: same frame, motor and battery for all models) costs $7,500 less than the 9.9 XX1 AXS build but is only 3.3(ish) pounds heavier. Put another way, the 9.5 is 53.6 percent cheaper than the 9.9 XX1, but only eight percent heavier.
The EX-e 9.8 XT is the model to get, courtesy
Personally, the best build in the line is the XT model. It’s under 40 pounds (claimed), has carbon rims, comes with tough and sticky SE tires, and has the fancy one-piece carbon bar/stem of most expensive builds. It has it all while carrying a sub-five-figure price tag.
Lastly, on SRAM AXS-equipped bikes (like my review model), the rear derailleur receives power from the bike’s battery via an “extension cord” pack. This pack clips in place of a standard AXS battery and connects to the bike’s wiring harness. If you completely drain an e-bike battery, there is enough juice left for about 200 shifts. Riders can bring a spare AXS battery as an extra precaution.
SRAM AXS derailleurs are powered by the bike’s main battery.
Model |; Weight in pounds| price
Fuel EX-e 9.5 | 43.94| $6,500
Fuel EX-e 9.7 | 41.99 | $7,600
Fuel EX-e 9.7 P1 Now | 41.99 | $8,100
Fuel EX-e 9.8 XT | 39.9 | $8,700
Fuel EX-e 9.8 XT P1 Now | 39.9 | $9,200
Fuel EX-e 9.8 GX AXS | 40.06 | $11,000
Fuel EX-e 9.9 XTR | 38.51 | $13,000
Fuel EX-e 9.9 XX1 AXS | 40.67 | $14,000
“P1 Now” fashions have a “premium” end and are painted and assembled at Trek’s headquarters in Waterloo, Wisconsin. Weight and construction kit are the same as standard models.
The Fuel EX-e arrives in stores worldwide today in limited numbers.
Sources : Trek’s Fuel EX-e, image credit Matt Phillips