Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In



Trek Fuel EX 9.8

The five-inch travel Fuel EX 9.8 is a superb blend of a bike: Light-and-tight handling yet packing supple, bottomless suspension.

Don't miss a moment from Paris-Roubaix and Unbound Gravel, to the Giro d’Italia, Tour de France, Vuelta a España, and everything in between when you join Outside+.

By Test Crew

Trek Fuel EX
Trek Fuel EX 9.8

Check out the Trek Top Fuel 9.8 review.

If you — and your bank account —  always choke on the phrase “quiver of bikes,” well then, we’ve found one rig that can multi-task: the Trek Fuel EX 9.8.

This five-inch travel bike impressed the test crew with its trail-taming features while retaining many positive cross-country traits. Like its four-inch cousin, the Trek Top Fuel 9.8, the Fuel EX 9.8 feels racy like its cross-country relative, but at the same time it offers a bottomless-feeling ride.

Price: $4,199.99
Weight: 25.75lbs (tested size large)
• 120mm travel
• Rear shock: Fox Float RP-2 w/proprietary Trek DRCV, Pro Pedal, rebound; 7.25×2.0 inch
• Full Floater linkage
• Magnesium EVO Link
• Oversized pivot bearings
• OCLV black carbon
• Net molded bottom bracket and headtube
• ABP Race thru-axle rear

Built out, the OCLV carbon platform Fuel EX we tested tipped the scales at 25.75 pounds. That’s a respectable weight for a five-inch trail bike, but doesn’t necessarily take your breath away. But out on the trail, the Fuel EX’s lineage to the race-bred Top Fuel becomes apparent.

“It’s light, agile and climbs very efficiently,” one tester said. “It rides much lighter than it weighs on the scale.”

Where the Fuel EX likely picks up its relative girth is in its build. The 9.8 is speced with stout Bontrager Rhythm wheels, 8-inch brake rotors front and rear, and a sturdy complement of structural components. Similarly, the XT drivetrain is reliable and affordable if not the lightest available.

The suspension design is fundamentally the same as that found in all Trek duallies – it sports a Full Floater front shock mount, ABP rear dropout pivots, and a magnesium Evo Link rocker. Additionally, the OCLV carbon fiber main frame features Net Molded bearing seats for the headset and bottom bracket and  oversized pivot bearings. All that hardware in conjunction with Trek’s proprietary Fox RP-23 DRCV (Dual Rate Control Valve) design rear shock serves up an almost bottomless feeling ride when the going gets rough.

It’s not often that a company gets a rear shock all to itself. But Fox built the DRCV shock to Trek’s specs for a reason. Basically it works like a low-volume, short-travel shock in the first half of its travel. The lower air volume in the early stroke is designed to help it stand up in its travel and behave more like a cross-country bike on climbs. As the shock strokes deeper into its travel, a second air chamber opens up, effectively increasing the air volume in the shock and flattening the spring curve. It’s meant to feel more pillowy and softer under big hits.

The DRCV worked as promised to keep the rear suspension light and tight in short travel situations, but it seamlessly opens to create bottomless travel in the deep stroke. We did have to adjust and re-adjust shock pressure several times to dial in most riders, but once adjusted it was a set-and-forget situation. Interestingly, there’s no discernable hint as to when the shock moves into one section of its stroke or another. It’s imperceptible.

We discovered great performance as well with the ProPedal. We were able to ride 100 percent with it “on” for stability under power, but never noticed any harshness through rocks. It blows open effortlessly for buttery suspension travel without missing a beat.

“The dual chamber rear shock was interesting,” said one rider. “I felt that the upper chamber fought the pedal bob. As soon as I hit that bottom chamber it was like, “Oh, where the hell am I?” It felt pretty bottomless.”

The Fuel EX is adequately stiff for accurate handling and efficient pedaling, but for some bigger, more aggressive riders the fork and head tube angle may cause some hesitance on descents.

As for climbing, the bike’s steeper — or steeper feeling — front end makes the Fuel EX climb like a cross-country rig. The rear end hooks up and tracks well on slower technical climbs, allowing for easy wheel-placing control up front.

That said, one rider found that the high bottom bracket took some handling and stability away, which caused him to blow off his line occasionally at high speed. But that wasn’t a fatal flaw, he said.

“Overall, it’s a perfect balance; a cross-country bike with five inches of travel. I like it.”


The five-inch travel Fuel EX 9.8 is a superb blending of bikes: Snappy and light feeling like a cross country rig, yet packing the bottomless suspension feel of a very effective trail bike. One of our smaller testers preferred the Fuel EX’s four-inch cousin, the Top Fuel 9.8, but not because of any perceived limitations of the five-inch platform.

“I didn’t need that much bike,” the tester said. “I felt like I could do just as much with the four-inch bike.”

Our testers with more height and weight, however, said they wouldn’t hesitate taking the Fuel EX out on Saturday morning cross-country race and then turn around and ride it on a multi-day epic. Another scenario is this: The Fuel EX 9.8 is a perfect marathon racer for a gnarlier course.

The bike is easy to sit, stand, pedal and plow through whatever’s coming at you, and likewise, when the trail tilts south, the travel is there when you need it.

“This is what I would call a ‘category killer,'” one tester said. “The five-inch bike that is best for XC racing and yet fun for all-day trail riding.”