The Fuel EX name first showed up in Trek's catalog way back in 2005 with just 100mm of suspension, but, like other long-lived models, every iteration since has either gained travel, gotten slacker and longer, or received other updates to make it a more capable trail bike. Seventeen years on and the 2023 Fuel EX gets a similar treatment, with an all-new 140mm-travel frame paired with a 150mm fork and sporting much more adjustable geometry.
For riders looking to get even more out of their trail bike, that adaptability even extends to it being compatible with a 27.5" rear wheel and a coil-sprung shock. And just in case you hadn't noticed, it sure looks a lot like their also-new Fuel EX-e
2023 Fuel EX Details
• Intended use: Trail riding
• Travel: 140mm rear / 150mm front
• Frame material: Aluminum, carbon fiber
• Wheels: 27.5" and 29"
• Sizes: XS - XXL
• Reach: 400 - 545mm
• Weight: TBA
• Price: $2,699 - $10,749 USD
The Fuel EX's frame is entirely new and looks quite different from the bike it's replacing, especially the meatier front-end and more complicated design at the seat tube and bottom bracket area. There's also a lot
more adjustability built-in to the new frame, including aftermarket angle-adjusting headset cups, two shock positions, coil-shock compatibility, and flip-chip pivot hardware that you can read about below. Suspension:
When it comes to the Fuel EX's back end, there are a few things you'll recognize and a couple you won't. Starting with what's new, Trek has bumped the travel on both ends up 10mm compared to the previous version, with 140mm being paired with a 150mm fork making this the biggest Fuel EX ever. And while none of the eight complete bikes come stock from Trek with one fitted, it's also the first version that's compatible with coil-sprung shocks. Helping on that front is a flip-chip at the lower shock mount that tweaks the leverage curve; one setting adds bottom-out resistance or works better with a coil, while the other is less progressive to suit an air can's inherently rising spring rate.
You probably won't be surprised to see Trek's ABP suspension layout on the back of the new Fuel EX. Those three letters are short for 'Active Braking Pivot' that describes the claimed advantages far more succinctly than I ever could. Instead of a Horst Link or having the pivot on the chainstay, ABP rotates concentrically around the hub axle. Wheel sizes:
Trek is selling the Fuel EX with both 27.5" and 29" wheels, putting the former on both the extra-small and small-sized bikes. They're also doing a small-sized frame on 29" wheels, while medium, medium/large, large, extra-large, and extra-extra-large will call come on 29" wheels.
And if you want to put a 27.5" wheel on the back of your Fuel EX, you can also do that thanks to all this adjustability. With the smaller wheel lowering the bike, Trek says you'll need to run a 160mm-travel fork and have the Mino Links set to the high position to keep the bottom bracket from feeling too close to the ground. Increased Adjustability:
If you're familiar with Trek's full-suspension bikes, you've probably already seen the flip-chip pivot hardware that connects the seatstays to the rocker link. Trek calls these the Mino Links and you'll find an updated version on this bike that offers the same 0.5-degree head angle and 8mm of bottom bracket height adjustment. I've always thought those were relatively conservative changes to the geometry, but a larger variance would require a more independent adjustment...
That's precisely what Trek has done for 2023, with Trek offering headset cups that can be swapped out to change the steering angle by a degree in either direction. The stock cups supply a 64.5-degree head angle, but those who want to go slacker (or steeper) can buy a set of cups that does both. You install them one way for 63.5-degrees or the other way for 65.5-degrees. The upper cup will drop in, Trek says, but you'll need a headset press for the lower one.
Those three head angle options and two Mino Link settings make for six geometry set-ups, which is why Trek has a new geo configurator tool on their website to help you sort out where to put what. They suggest using the Mino Links to fine-tune things: "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.
There's also a 34.9mm seat tube, a threaded bottom bracket shell with an ISCG-05 chain guide mount around it, and the world's longest downtube protector that should prevent damage from both rocks and tailgates. It's also nice to see full-length internal housing guides from front to back that should make maintenance easy while also giving the frame a tidy look. The downtube storage compartment has been carried over to the new design, of course, and they also added it to the new aluminum Fuel EX frame as well.
While it seems like Trek has put all the things onto the latest Fuel EX, there's one that they left off: Knock Block. The headset-integrated steering stop is designed to keep fork crowns from smashing into the straight downtube (that Trek says makes for a stiffer frame) on some of their bikes, but the 2023 Fuel EX has gone back to a curvy downtube that provides plenty of clearance. This is a good thing. Geometry
There are no surprises when it comes to what's changed: the new Fuel EX gets a longer wheelbase, longer reach, a steeper seat angle, and a slacker head angle.
Up front, the previous Fuel EX could be set as slack as 66-degrees with its 140mm-travel fork, whereas the new bike can be relaxed all the way to 63.5-degrees if you're using the aftermarket headset cups explained above. Are your trails too flat and slow for that number? You can also steepen the bike up to 66-degrees using the same cups, all without drastically messing with the bike's seat angle. Speaking of seat angle, those are steeper across the board, with the large sitting at 77.2 versus the old large's 75.5-degree number.
Front-end length has grown a bit as well, with our large-sized test bike being 485mm (Mino low) versus 470mm for the old bike. It starts at 400mm for the smallest bike and goes all the way out to 545mm for the biggest size. Effective top tube length has done the opposite, however, going from 634mm to 626mm for a large due to the steeper seat angle.
This is also the first Fuel EX that gets size-specific chainstays, and four lengths are used between the extra-small and extra-extra-large sizes. Much like Norco does, Trek accomplishes this by using slightly different main pivot locations rather than manufacturing different chainstays; extra-small to medium sizes get a 435mm rear-end, medium-large and large 440mm, extra-large 445mm, and the big boi has 450mm chainstays. 9 (ish) Fuel EX Models
There are nine different 2023 Fuel EX models that range in price from $2,699.99 to $10,749.99 USD, but only eight of them are new bikes. That first price is for the EX 5 that's actually a carry-over using last year's aluminum frame, which means it has 130mm of travel and a 140mm fork in the shape of a RockShox Recon Silver.
The new bikes start with the aluminum EX 7 which costs $3,700 and aluminum EX 8 that goes for $4,300 USD. These get the same features as the pricier carbon bikes, including the storage compartment, angle-adjusting headset, and coil-compatibility. The EX 8, spec'd with Fox Rhythm 36 fork, an XT drivetrain, and Deore four-piston brakes, looks like a smart choice. Carbon fiber shows up next with the EX 9.7 which gets a similar-ish spec but costs $4,700 USD.
If you have more than twice that to spend, the 9.9 XX1 AXS gets all the expensive parts and will set you back $10,749 USD.