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The Takeaway: Trek’s 2020 Fuel EX has more travel, is stiffer, and built with bigger parts. It’s a bit heavier and more capable in rowdy terrain, but still an excellent all-purpose trail bike
Expanded range of sizes and colors, but no more women’s models.
140mm forks and 2.6-inch tires on all models
Fox 36 forks on top-of-the-line models
Lifetime frame warranty returns
Price: $2,100 to $7,500
Weight: 29.1 lb. (Fuel EX 9.9, size 17.5)
Trek’s Fuel EX was an excellent lightweight trail bike, with notes of XC race in its bouquet. For 2020 the EX effectively underwent a training montage worthy of an 80’s movie and emerged bigger and badder. It is up to 140mm travel in the front (still 130mm in the rear), longer, slacker, stiffer, and comes with bigger tires. The new EX is a trail bike with hints of enduro. Yep, it’s heavier: The top of the line model weighs about 29 pounds on our scale. But it also has a trap door and hidden storage in the downtube.
The 9.9 reviewed here, and the $5,500 9.8, have Trek’s premier shock technologies and hearty Fox 36 forks—features lower cost EX models don’t get, which is a shame, because the 9.9 is a beautifully balanced and capable trail bike. The rear suspension is superb, offering a blend of support, sensitivity, and control that might be unmatched. The suspension handles bumps like it has more travel, but pedals like it has less.
The Fox 36 with GRIP 2 damper is very stiff, which helps keep this bike on the line you want to ride—the 2020 EX’s improved rear end stiffness helps too—and the quality of the travel is lively yet controlled. Yes, I’m gushing, but this suspension deserves it. It’s too bad Trek didn’t see fit to fit this bike with a decent dropper though. The stock Bontrager post is sticky and sluggish.
The longer and slacker geometry provides a more centered feel when you’re working the trail with the saddle dropped. The bike’s steering is light, and the bike climbs technical singletrack very well—a nice suspension platform and crisp pedaling manners help. On downhills, it’s very sure-footed and even rides a little bigger than its travel and geometry might suggest.
There are a lot of great trail bikes you can buy right now. This EX makes a strong case that it’s one of the very best.
The 2020 Fuel EX 29er is more than just redesigned; it’s repositioned. Trek launched the new Top Fuel earlier this year, transforming it from an XC race bike to a longer-travel (115/120mm) and more trail-oriented bike. That narrowed—practically eliminated—the gap between it and the 2019 130/130mm Fuel EX. But the 2020 Fuel EX also bumps up in travel and gets a little burlier. It’s now a bigger trail bike tiptoeing toward the enduro category.
Rear travel remains 130mm, but on the front are 140mm forks, with higher-end carbon models using Fox’s 36. The frame is stiffer, and gets longer (10 to 20mm depending on size). Angles change too: the head tube is a degree slacker (66 in low, 66.5 in high), while the seat tube gets a degree steeper (75 in low, 75.5 in high). As you can tell, the frame still employs a geometry-changing flip-chip.
Wheel Size: 29 inch
Shock: Fox Factory Float Reactiv ThruShaft
Fork: Fox Factory Float 36 Grip 2, 140mm
Crankset: SRAM X01 Eagle
Rear Derailleur: SRAM X01 Eagle Dub
Cassette: SRAM XG-1275 Eagle, 10-50
Brakes: Shimano XT 4-piston hydraulic disc, 200mm (f), 180mm (r) rotors
Seatpost: Bontrager Drop Line Elite
Rims: Bontrager Line Carbon 30, 30mm internal width, tubeless ready
Tires: Bontrager XR4 2.6-inch
There’s also a new trap door in the downtube—carbon models only—that provides that sweet, sweet storage in the downtube. An organizer roll—included—has pockets for a tube, Co2 cartridge, inflator head, and tire lever and keeps it all from rattling around. A plastic side-load bottle cage is included with the bike. We’ve also heard rumors that a tool that fits in the headtube will arrive later this year.
The switch to longer and slacker frame geometry brings with it shorter offset forks. This isn’t shocking—almost every new mountain bike that rolls out with uses a shorter offset fork. But for Trek, it’s a more significant change because it means rolling back from a feature it heavily promoted for many years. Its Genesis/G2 29er geometry is based around longer (51mm) offset forks. But that geometry has its roots in the beginnings of the 29er movement, when brands were trying to make 29ers handle like 26-inch-wheeled bikes (that was a thing), and also the days of shorter and steeper geometry.
But that era is over, and Trek is moving on, “Modern geometry and its longer reach and slacker headtubes requires a smaller offset to put the front wheel in an appropriate spot under the rider,” said Travis Ott, Trek’s mountain bike brand manager .
Fork offset isn’t the only place where Trek is walking back from a signature feature: Full Floater, the “floating” shock mount that was a feature of the Fuel EX for several generations is gone, and the bike now uses a fixed lower shock mount.
Trek engineers in the past said that Full Floater let them achieve a better shock rate—for better suspension performance throughout the travel—than they could with a fixed lower mount.
But that was then. The new generation of shocks, Trek says, offer the performance that previously was only achievable by using Full Floater, making the floating shock mount redundant. As a secondary benefit, the fixed-lower shock mount also helps Trek improve frame stiffness.
Higher-end EX models get a custom Fox Float shock with a list of Trek-only features. There’s a mini-piggyback reservoir that dissipates more heat in demanding situations, a thru-shaft design to reduce friction, and Reaktiv regressive damping for a firm pedaling platform without compromising sensitivity.
There’s also a numbered rebound knob to make setup easier. Trek representatives told me that customers found rebound settings like “15 clicks in” or “seven clicks out” confusing, and as a result would ride improperly tuned suspension. Now, Trek’s setup information can provide an easily understandable setting like “6” that matches a number on the knob.
The 2020 Fuel EX fits up to 2.6-inch tires front and rear. And to ensure “all” 2.6 tires fit, the EX’s forks get a custom spacer that slightly increases its axle-to-crown length compared to a stock 140mm fork and provides more crown clearance.
2020 Fuel EX frames come in aluminum or carbon. And all carbon frames are all carbon—no more carbon front ends with aluminum rear ends on mid-tier models. All frames have a lifetime warranty. Carryover features include Trek’s Knock Block headset, which prevents the bars from swinging around and damaging the top tube, and anti-rattle hose and housing with internal routing.
Gender, Sizing, and Wheel Size
The 2019 Fuel EX came in three women’s models and six unisex models. The 2020 EX line consists of six models with no women’s models. Instead, all 2020 EX models are available in a greater frame-size range and two colors. This, Trek argues, gives all riders more options to choose. None of the 2020 models get women’s saddles. Potential buyers will need to negotiate with a Trek dealer if an EX’s stock saddle doesn’t work for their anatomy.
The 2020 Fuel EX comes in eight sizes—extra small through double extra-large. The extra-small bike has 27.5 wheels, but the next size up comes with either size 27.5- or 29-inch wheels. All other sizes get 29-inch wheels only.
The Fuel EX Family
The new EX comes in six “mainline” models priced from $2,100 to $7,500. The EX is also customizable through Trek’s Project One program.
The three least-expensive models—$2,100, $2,900, $3,500—use an aluminum frame, and the three most expensive models—$4,100, $5,500, $7,500—use the full-carbon frame. Frame only is offered for both materials: $2,000 for aluminum and $3,300 for carbon.
All models use 140mm forks, however only the two most expensive bikes—the 9.8 and 9.9—get a Fox 36 fork. All other models use a Fox 34, RockShox 35, or RockShox Recon. On the other end, the least-expensive model uses a RockShox shock, but all other models use a Fox Float. You need to step up to the $3,500 EX 8 before you get the Reaktiv regressive damper in the shock, and it’s not until you hit the $5,500 EX 9.8 that you access the thru-shaft damper design.
So yeah, you don’t get *all* the good stuff—carbon frame with internal storage, 36 fork, thru-shaft shock, Reaktiv damping—until you spend $5,500.
All but the cheapest model come with 1x12 drivetrain and tubeless-ready rims. All models come with Bontrager 2.6” wide tires, dropper post, lock-on grips, and hydraulic disc brakes.
Not surprisingly, Trek sent me the top-of-the-line 2020 Fuel EX 9.9 X01 ($7,500). This model and the 9.8 have all the new features and all of Trek’s premier technologies.
But most EX models come with much different forks and shocks that will significantly affect how the EX performs— a bike with a 36 on the front rides much differently than a bike with a 34 on the nose, even if everything else is the same. So I’m only comfortable extending my impressions to two of the six 2020 EX models. I hope to ride one of the less expensive aluminum models to see how it rides and offer those impressions in a stand-alone review.
I hope they can come close to the performance of this bike because this 2020 EX 9.9 is excellent. It’s not the same bike it was before: the new EX is a little slower on the climbs than the old one, and a bit heavier, but a lot better everywhere else. It’s still a capable and versatile bike, but its window has shifted from marathon racing and trail bike, to trail and almost-enduro bike.
The rear suspension is beautiful; as close to ideal as any bike I’ve ridden. It’s sensitive where you want it to be, firm and crisp where it should be. It feels deep and controls big hits very well, and there’s a nice platform for pedaling, and to pump and pop off of when you’re playing.
The Fox 36’s GRIP2 damper continues to set the bar for performance. Once you get its settings right—and it may take some fiddlin’ with the four clickers to get there—no other fork matches its combination of traction, control, stiffness, and weight. Its performance pulls this bike’s capabilities to a new level, especially in demanding terrain.
The new geometry is well balanced: You can push this bike hard in pretty demanding terrain, and it still climbs tight and technical trails well, and without fighting the front wheel (too much). The EX’s seat tube angle isn’t crazy-steep for a modern mountain bike, but it doesn’t need to be: the Trek’s Reaktiv damper’s platform holds the bike up in its travel better than similar bikes, preventing the rider from being pushed into the back seat because of increased shock sag from weight transfer. So even though the seat tube is “only” 75/75.5, it rides a bit steeper.
The platform also assists the EX’s pedaling efficiency. When I think of a nearly 30-pound trail bike with 2.6 tires, I don’t think quick and crisp. But this EX feels firm when you’re on the pedals and climbs lighter than a 29-pound trail bike should.
And it’s about here where I need to address my one complaint about this bike: The Bontrager dropper post. If this was a $2,000 bike, I might—might—be able to excuse its sluggishness and stickiness. But on a $7,500 bike, its performance is shameful—it performs exactly like a product that was chosen to save a few bucks. Excellent options like the BikeYoke Revive, Fox Transfer, and RockShox Reverb (the latest one), exist: This bike’s performance and high-end price deserve one.
I’m a fan of the longer reach. I’m 5’8,” and in the previous generation EX I sized up to an 18.5 because the 17.5 felt short and squirrely. But the reach of the new generation in 17.5 is within a few millimeters of the 18.5 from the previous generation. In the saddle the cockpit does feel a touch short because of the steeper seat angle (I slammed the saddle back because the rear suspension rides high making the seat angle feel even steeper), but, saddle dropped, I felt perfectly centered in the bike and not hanging over the front wheel.
It’s a great time to be a mountain biker because there are so many great trail bikes you can buy. The Fuel EX 9.9 and 9.8 are pricey bikes but have a collection of performance and features that few other bikes can match right now.
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