It has been a decade since Trek first released the Fuel EX. Mountain biking as a sport has changed quite a lot over those years, as has the Fuel EX. On this, the ten-year anniversary, Trek has released an all-new Fuel EX that is a dramatic change from the prior iteration. There's a new frame design, revised geometry, frame storage, and a host of adjustments that can make the Fuel EX morph into any kind of trail bike you want. There's a lot to unpack here, let's not waste time.
- OCLV carbon and alloy frame options
- 29-inch wheels (XS is 27.5 only, small is available in 27.5 or 29)
- Mixed-wheel compatible with Mino link and 160mm fork
- 140mm (5.5-inches) of rear wheel travel // 150mm (5.9-inches) fork travel
- ABP suspension design
- Tapered headtube with adjustable headset cups
- Guided, internal cable routing
- In-frame storage with BITS bag
- BITS tool in the headtube
- Adjustable suspension leverage chip
- Full downtube protection
- Size-specific chainstays
- Threaded bottom bracket with ISCG05 mounts
- Boost 148 rear spacing with 12mm through axle
- MSRP $10,749 USD (As tested)
When Trek launches a new bike there tend to be more leaks than a sunk boat. Down to its prominent display in Brandon Semenuk and Kade Edwards' Parallel 2 video, the new Fuel EX is a surprise to few. Regardless, the new frame lines and design are indicative of an entirely new platform. Trek is offering the Fuel EX as a complete line with a broad selection of build kits and price points.
Trek went all in with the geometry updates here. Yes, the longer, slacker, steeper trend is there but certainly, that is a good thing and though the changes are pretty big, the Fuel EX isn't outlandish by any stretch of the imagination. Depending on the size, the Fuel EX has grown by 20mm in reach. The head angle comes out of the box 1.5-degrees slacker (and can go slacker still) and the seat angle steepens by 2 degrees.
The Fuel EX ships with the Mino link in the low position, giving it a 64.5-degree head angle. Going to high will steepen that to 65 degrees. Trek is offering an aftermarket headset insert that will allow riders to alter the head angle by plus or minus 1 degree, meaning riders could go as slack as 63.5 degrees but then bump it up to 64 degrees with the Mino in the high position (slack with more pedal clearance). Trek has a geometry tool on the Fuel EX page to help riders discover all of the possible adjustments and scenarios.
Additionally, there is a flip chip at the lower shock mount. In stock form, the chip comes in a more neutral progression setting, ideal for air shocks and an overall more supple feel. Flip the link to a more progressive setting and the Fuel EX takes on a more aggressive leverage curve and becomes coil compatible.
In all, there are seven new Fuel EX builds along with both carbon and alloy frameset options. The two alloy builds use Trek's Alpha Platinum aluminum and does have in-frame storage. The five carbon builds are Trek's OCLV and also have in-frame storage.
Both alloy builds, EX 7 ($3,699) and EX 8 (4,299), use Shimano 12-speed drivetrains and Shimano 4-piston brakes. The EX7 runs a RockShox 35 Gold RL fork and FOX Performance Float Evol shock while the 8 gets a bump to the FOX Rhythm 36 and FOX Performance Float X. While the EX 8 may not be the higher-end aluminum build that many riders shout out for, the parts blend is solid without being flashy.
Trek delineates its carbon offerings by the 9 designations, with builds starting at 9.7 and moving up to 9.9. The Fuel EX 9.7 (4,699) is a blend of parts from both the 7 and 8. Riders get the nicer suspension from the 8 but the drivetrain from the 7. For those wanting to dip into carbon waters, this is a good place. The suspension is great and the drivetrain is rock solid, albeit a bit weighty.
The EX 9.8 GX AXS ($7,699) build tells you the drivetrain already. The fork bumps a little to the FOX Performance 36 and the Float X stays on. Riders do get the bump to Bontrager's Line Elite carbon hoops. Robots aren't cheap and we're guessing Trek went with the SRAM Code R brakes to save a little coin. We'd choose derailleur cables over Code Rs but riders can make that choice for themselves.
Next is the 9.8 XT ($6,249). Every part from the 9.8 GX AXS carries over except the obvious drivetrain and brake swap to Shimano's XT group.
Lastly are the EX 9.9 XX1 AXS ($10,749) and XTR ($9,749) builds. As one would expect, everything is top-notch. FOX Factory suspension, Line Pro carbon wheels, RSL carbon bar/stem combo; it's all there. The XX1 AXS has said drivetrain and Code RSC brakes while the XTR build has the appropriately matched Shimano drivetrain and brakes.
On The Trail
It isn't often if ever, that one says a mountain bike looks just like an e-bike, but that is exactly the case with the new Fuel EX. When we attended the online launch, we had to chuckle as the Fuel EX looks just like the Fuel EXe we had recently tested. In picking up our test bikes in Whistler, we were nervous that onlookers may accuse us of riding an e-bike on an unsanctioned trail. Our uphill pace probably put us well in the safe zone.
Our two Vital staffers grabbed a medium and extra-large Fuel EX 9.9 XX1 AXS for a little jaunt on Lord of the Squirrels. This is a popular trail in the area, and we were in luck as it had just opened the day before. In all, our ride would carry us over 20 miles with 4,000 feet of climbing. As we laid out our plan to Trek, they replied that it was the perfect ride for the Fuel EX.
Our bikes were shiny and new, with brakes that were not even bedded. Fortunately, Trek did have the time to chop down the bars for our medium test bike. We set our FOX Float X shocks to 30% sag and lead with the PSI chart on the FOX 36 forks, putting in the recommended amount of air. After that, we boldly went off on our ride. Vital would normally not recommend such a ride without some shakedown, but it was Crankworx, baby! #sendit
Our given route for this ride had us start off on a paved climb, nothing too steep. From there, we were to head into something I like to call Face Punch Alley. After that, things were pleasant for some miles, and the "meander in the woods" stigma around this ride set in. At some point, near a lookout deck, the trail made a right turn and went up. The going up did not stop for many miles. Somewhere along the line one of us broke and determined this climb was really damn hard. The other person rode his XL bike swiftly up the mountain, further demolishing my spirits. At least the flies and mosquitos were really bad.
Right out of the gate on the paved portion, the Fuel EX proved itself a happy climber. Our two-man crew breezed along in an efficient and comfortable manner. We'll tip our cap to the Fuel EX for being a rather natural feeling ride. Once thrown into the more technical and looser bits of the climb, the EX held its own. Considering the circumstances, there were a number of occasions we were thankful to be on this particular bike.
There are plenty of sections of the climb that are smooth and we did goof around with the climb switch, particularly in the hurt locker. It wasn't so much that the bike needed it but we wanted that emotional gain. Despite having a load of hydration on our back, the Fuel EX didn't get too light on the steeper bits.
DH/Technical Performance/Fun Factor
After far too much climbing and several snow fields, we reached the top of our ride. Our team received some brownie-to-mouth resuscitation and broke out the camera for beauty shots to let the sugar sink in.
During the initial part of our descent, we felt the Fuel EX was a little too glued to the ground. There's definitely a time and place for this sort of character but based on what we were taking in with the trail, we wanted more pop. After some adjustments to the suspension, we were off again. Then we pulled over again and tweaked some more. The third time was the charm and we were off to the races.
Knowing that the bike is not defined by a single character is pretty fantastic.
We'll say that it speaks well of both Trek and FOX to have such an adjustable nature. Knowing that the bike is not defined by a single character is pretty fantastic. While we will loudly add the disclaimer that neither of us had ever been on this bike and one of us was riding blind, our nerves were calm aboard the Fuel EX.
There are a number of blind rollers and punts on the downhill and after plowing through a few of them, both the trail and the bike became very predictable. Letting the bike off the leash revealed a glorious ride. We were really impressed with the Fuel EX and still had miles of trail to go.
Rear Suspension Performance
FOX's Float DPX was one of our favorite shocks. We often called it the little shock that could. The new Float X is all that and more. For being a parking lot tune with a trail-side adjustment, we could not have been happier with its ability to tame miles of roots and rocks. Lord of the Squirrels is not the heaviest trail around but it is long and there are plenty of bumps. From slabs to roots and square edge hits; both the Float X and Trek's ABP handled it masterfully.
Where did the suspension excel?
There are tons of small to mid-sized impacts on the downhill. The FOX suspension smoothed it all out, and we were genuinely impressed with the moments of magic-carpet feel. Were it not for our gloveless hands' disagreement with the Bontrager grips, we would have felt fresh as a daisy.
We used the full travel on our test bikes but felt well supported when fluttering through higher-speed rough sections. Additionally, the Fuel EX was well-balanced front and rear, letting us set up properly for a variety of sections.
In-frame storage is becoming less unique but we always appreciate having it. Additionally, the Bontrager tool in our steerer was quite handy for trail-side adjustments. We're eager to get our long-term test bike and play around with all of the adjustments on the Fuel EX. The Bontrager RSL one-piece bar and stem is unique, though time will tell if it is a feature.
When Trek told us we had outlined the perfect ride for the Fuel EX, they weren't kidding. In its stock form, this is as clear a representation of a trail bike as one can get. Mountain bikers that do big climbs with long descents will love the Fuel EX line. We have to imagine that even more can be squeezed out of this bike with a longer fork, slacker head angle, mixed-wheel setup, coil shock, and what-have-you. Riders can tweak their little hearts out. Regardless, out of the box, this might be our favorite Trek we've ridden to date.
We wouldn't characterize the Fuel EX as a featherweight. To be fair, it is not marketed as such but we had hopes that with all those light, high-end parts, it would feel as such. Regardless, the bike never felt piggish and conversely, it was soundly planted in the rough stuff.
Our medium tester spun his 30-inch legs as fast as he could to keep pace with Captain Climb, and the Fuel EX obliged as best it could. Bursts of power out of corners resulted in immediate acceleration. In short, the Fuel EX is an efficient machine.
It's 2022 (or 2023 according to most bike brands). If a brand's top-shelf superbike makes noise on the trail they should turn off the lights and quit. Of course, the 9.9 XX1 AXS was quiet. All we heard was the scurry of rocks beneath us punctuated by moments of uncontrollable laughter.
If Trek is buying, we'll take the XX1 AXS build kit but that isn't how things work. If it were our money and the Fuel EX line was laid before us, we'd give the nod to the 8, 9.7, or even the 9.8 XT if we were feeling fancy. All of these platforms will get you comparable performance and money left over to stuff that downtube full of taquitos.
Vital has taken in a lot of Trek bikes for long-term reviews over the past four years and never had much of an issue. When we look over the Fuel EX, we see increased levels of frame protection and much of the same, nicely finished build qualities we've come to expect from Trek. Whenever there are more things to adjust (leverage rate chip, headset cups) there will always be an increase in the likelihood of creaks. We cannot speak directly to those on this bike, but it is out there.
...the new Trek Fuel EX is a damn fine trail bike right out of the box, no matter your riding style.
What's The Bottom Line?
Vital sent two testers out on the Fuel EX. One of them punished himself for too many hours editing bike reviews, the other guy took off up the hill. If it means anything, those roles were reversed on the descent. In the end both riders made it back to the truck with giant smiles on their faces. Ultimately, it was concluded that the new Trek Fuel EX is a damn fine trail bike right out of the box, no matter your riding style.
Look for the long-term review coming later. For now, head to TrekBikes.com for more details.
View key specs, compare bikes, and rate the new Trek Fuel EX in the Vital MTB Product Guide.
2023 Trek Fuel EX FAQ’s
What's new about the frame?
- An aggressive, forward-leaning visual redesign
- More travel: 150mm front/140mm rear
- Size-specific chainstay lengths
- Threaded bottom bracket
- Adjustable geometry via Mino Link and aftermarket angled headset cups
- Adjustable suspension progression provides more support for coil shocks or extra-aggressive riders looking for more bottom-out resistance
- A 34.9mm seat tube for fitting burlier, more reliable dropper posts
- Guided internal cable/hose routing for simplified maintenance and less noise
- A full-length dual-density downtube guard for protection from debris and during shuttle runs
- Alloy models now get internal downtube storage!
Do any frame sizes feature curved top tubes for lower standover?
Can XS and S bikes with 27.5” wheels run a 29” front wheel?
No, there’s not enough fork clearance.
In which Mino Link position does the bike ship?
Low/slack (64.5 degrees)
What happens if I flip the Mino Link position to High?
You’ll get a half degree steeper head angle (65 degrees) for quicker handling and an 8mm higher bottom bracket for more ground clearance.
How does the adjustable headset work?
You can swap out your headset cups to get a full degree of head angle adjustment without affecting any other measurements. The bikes come stock with the zero degree cups, but SKU W5295319 (sizes XS-L) or W5295274 (sizes XL-XXL) gets you the angled upper cup and SKU W5294449 (all sizes) gets you the angled lower cup.
The upper cup is a drop-in part, but the lower cup needs to be pressed in with a standard shop headset press. The cups have notches and laser-engraved guides to help you install them straight. For more detailed installation instructions, watch the Fuel EX service video on Trek U.
Install the angled cups in the indicated slack position to get a 63.5 degree head angle for more stability, or rotate 180 degrees to get a steeper 65.5 degree head angle for quicker handling.
You can install the headset cups in the slack position and use the Mino high setting to maintain BB height and avoid pedal strikes, all while keeping a 64 degree head tube angle. Need even higher and steeper? Use the Mino high setting and the steep head tube cup setting for a 66 degree head tube angle.
Are all sizes compatible with a water bottle?
Do all frame sizes use the same wheel size?
- XS: 27.5-only
- S: 27.5 or 29
- M and up: 29
What is the maximum tire size?
Frame clearance for 2.5” wide tires on both 27.5 and 29 models.
Is it compatible with other wheel/tire sizes?
Yes – this bike is mullet compatible. Riders can run a 27.5 rear wheel for better bike-to-body clearance and more agile handling. To keep the bottom bracket height reasonable and avoid pedal strikes, we recommend a 160mm fork and running the Mino Link in the High (65 degrees) position.
Are these bikes tubeless compatible? What additional parts are required?
Fuel EX 7 and up come with everything you need to set the wheels up tubeless out of the box. No additional parts required. Fuel EX 5 comes with tubeless ready rims and rim strips, but no valves, sealant, or tubeless ready tires.
What is the maximum fork axle-to-crown and travel?
See charts below. Approved for the longer Fox 38 /Rock Shox ZEB 160mm.
How much dropper post insertion does the frame have?
Does it have any accessory mounts (kickstand, racks, fenders, lights)?
Fuel EX 9.8 and 9.9 come with a Blendr-compatible bar/stem. Otherwise, Fuel EX is a purpose-built trail bike and doesn’t have mounts for a kickstand, racks, or fenders.
What is the maximum chainring size? Minimum chainring size?
Max: 34T round, 32T oval; Min: 28T
What is the chain line?
What is the crank interface?
BSA 73mm, threaded
Does it have ISCG mounts?
Which version of Knock Block does it use?
No Knock Block here.
What is the rear brake mount? What is the max rotor size?
180mm direct post mount (203mm max)
Which aftermarket shocks are compatible?
We know that the following shocks will fit. Other shocks may fit, as there is generous clearance, but should be checked for frame clearance at full suspension compression.
- All FOX, air and coil
- All RockShox, air and coil
- o Flight Attendant fits all sizes, but with no bottle clearance on sizes XS, S 27.5, and S 29. - DVO, air and coil
- PUSH shocks
- o No bottle clearance on sizes XS, S 27.5, S 29.
- EXT Storia coil
What size hardware is needed for aftermarket shocks?
Fuel EX takes a 185mm x 55mm shock with an industry standard 54mm x 10mm upper Trunnion and 40mm x 8mm lower standard pin mount. Fox and RockShox lower eyelet hardware in the 40mm x 8mm size are available on B2B.
Are there different sizes chainstays for size-specific stays?
Size-specific chainstay lengths are achieved by altering the main frame, not the chainstay. This means replacement chainstays are the same for all frame sizes (for a given wheel size).
Will the alloy stays work on carbon frames and vice versa?
Will there be painted replacements for paint-matched storage doors?
Yes, replacements can be found in each model’s Trekbikes.com page under Bike Tech. Note that the entry-level models get a black storage door.
Will it be available in Project One?