Trek Fuel EX 5 Gen 5 Review



Words by Travis Reill  |  Photos by Dusten Ryen & Brian Niles
Sponsored by Leatt & Tifosi Optics

With trail bikes in Trek’s lineup reaching five-digit prices, it is nice to see the industry giant offer a full-suspension trail bike that doesn’t break the bank. Trek was kind enough to send us the Fuel EX 5 to ride and review in our budget-bike shoot-out. At just under $2,500, the Fuel EX 5 is one of the most expensive bikes on test. We were excited to get the Fuel EX 5 out on the trails and see how it stacks up against the others in our test bike group.


• 130mm single-pivot ABP
• Flip-chip adjustable geo
• HTA 66.5 (high setting)
• STA 75.5 (high setting)
• REACH 475 (Large, high setting)


  • Big-brand Security

  • Highest Quality Frame On Test


  • Short dropper post

  • Wide, Heavy wheels

  • Least Pedaling Support Of The Group


Many of us are familiar with Trek’s trail-busting Fuel EX line. The Gen 6 Fuel EX saw added travel – not to mention a new frame design – but that doesn’t mean there isn’t room for the shorter-travel younger sibling out on the trails. With 140/130mm of travel and relatively moderate geometry, the Trek Fuel Gen 5 has been a trail bike many have reached for years.

Trek Fuel EX 5 Gen 5 Review


Trek’s Fuel EX 5 features Alpha Platinum Aluminum. Trek boasts their aluminum “is continuously cold extruded and butted at multiple points, and hydroformed into sophisticated tube shapes for maximum strength and minimum weight.” The Fuel EX also has Trek’s Knock Block headset system, which prevents the handlebars from hitting the top tube and causing damage in a crash. Cables are internally routed, and the frame is offered in two color options: black, or the black and yellow we received.

The Fuel EX is offered in seven sizes, from XS to XL. X-small and small frame sizes come with 27.5-inch wheels and a pronounced dip in the top tube to help with standover height. Sizes medium and up are all equipped with 29-inch wheels. If you are familiar with Trek’s sizing, you will know that they also offer a medium/large size for those in between the two sizes. This is the only “in-between” size offered.

Trek’s Mino Link allows you to change the Fuel EX’s geometry. Switching from high to low will slacken the bike by 0.5°, drop the BB by 6mm, and shorten the reach by 5mm. While the bike comes with a 140mm travel fork, Trek gives allowance for bumping up to 150mm to improve descending capability.

Trek Fuel EX 5 Gen 5 Review


The Fuel EX is essentially a linkage-driven single-pivot with one key difference—a pivot at the rear axle. Trek calls this their Active Braking Pivot (ABP) design. On most suspension designs, braking is considered to negatively impact the rear suspension’s ability to absorb impacts and provide traction. Trek’s ABP design aims to allow the rear suspension to remain more active under braking forces.


The Fuel EX 5’s geometry remains relatively moderate compared to today’s trail bike trends. For clarity’s sake, I’ll share the geometry in the “high” setting of the geometry-adjusting Flip Chip. The head tube angle is 66.5° and is paired with a 75.5° seat tube angle. The Stack Height ranges from 559mm to 623mm and Reach lengths range from 400mm to 500mm. Our size large came in at 609mm and 475mm respectively..

The BB height is 341mm in X-small and small, then 346mm for medium and up. Similarly, the BB drop is only 14mm below the axles on the two smallest sizes, and 28mm on sizes medium and up to account for the larger wheels. 436mm chainstays feature across all sizes. Our size Large Wheelbase totalled 1211mm.

Trek Fuel EX 5 Gen 5 Geometry


For the Fuel EX 5, Trek only offers two build options: a higher-end, 9.8 AXS Gen 5 and the budget-friendly EX 5 they sent us at $2,499. Leading the charge on our test bike was a Rockshox Recon Silver with the Motion Control damper and lockout. In the rear, there was a X-Fusion Pro 2 shock with “open” and “climb” positions.

The drivetrain is a complete Shimano Deore M6100 12-speed build, with Shimano’s 10-51 tooth cassette and a 30-tooth chainring. Shimano also handles the brakes, with 2-caliper hydraulic stoppers and 180mm rotors. 35mm width Alex MD35 wheels are laced to Bontrager hubs, and roll on wide 2.6 Maxxis Rekons. Bontrager makes up the rest of the build with tires, cockpit, and saddle—with the exception of a TranzX dropper post at a short 130mm drop length.

Trek Fuel EX 5 Gen 5 Review


With a brand name as large as Trek, our expectations with the Fuel EX 5 were reasonably high. Even with a more budget-friendly component build, we figured Trek’s proven platform would shine through, regardless of the parts hanging from the frame.

When we tested the Trek Fuel EX 5 on the trails, we found it best suited for riders looking to put in miles. Its very moderate 66.5° headtube angle—the steepest of any of the bikes on test—puts the rider’s body more toward the front of the bike. This allows for a comfortable pedaling position, especially on climbs, which the Fuel EX 5 did reasonably well on. That forward-heavy position also provided good handling on the relatively techy bits of the climbs.

Even with a steeper headtube angle, the Fuel EX 5 wasn’t overly twitchy on faster descents. With 130mm of rear travel, it tackled some rough and chunky trails reasonably well, but finding its limit was quite easy for our aggressive riding crew. It also jumped decently, although the suspension had been firmed up quite a bit. This was done out of necessity, to add support to prevent harsh bottoming out on harder hits. Less aggressive riders looking for a more conventional light-duty trail bike may not feel the need to do the same.

Trek Fuel EX 5 Gen 5 Review

One thing that seemed to hold the Trek Fuel EX 5 back while descending was the dropper post. Our size large EX 5 came with a 130mm dropper, a much shorter length than we’re used to for a size large frame. This meant having quite a bit less post insertion to get proper saddle height for climbing. When it was time to point the EX 5 downhill, the seat, even when dropped all the way down, was high enough between your legs to make handling the bike uncomfortable.

Initially, the expectation was that the Trek Fuel EX 5 might be the most efficient and best pedaling bike on test. However, we found that this wasn’t the case once we hit the trails. The bike’s geometry teased that as the case, but something seemed to be holding it back. After several of our testers spent considerable time on the Fuel EX, we concluded that the rolling weight of the wheels made the bike seem sluggish. We’re not sure why a trail bike is spec’d with 35mm inner width rims, but that, combined with 2.6 width tires, surely hurt the Trek’s performance when it came to rotational efficiency.

As with many of the other budget bikes in the field, the suspension and brakes were also where the Trek Fuel EX 5 came up short. The Fuel EX 5 shared the same suspension, and many of the same issues, as the GT Sensor Sport. The fork and shock both seemed sticky, and there were very few adjustments. The air pressure X-Fusion recommended for me (Travis) essentially turned the bike into a hardtail. When I let air out to get an appropriate SAG, the shock bottomed out hopping off a curb. Regarding brakes, the Shimano 2-pistons performed better than some of the other brakes on the budget bikes, but they still left us wanting a bit more power.

The Wolf’s Last Word

With much more moderate geometry and an over-the-bars feel, we anticipated the Trek Fuel EX 5 to be our most efficient pedaler on test. While it climbed and descended reasonably well, it wasn’t a bike that seemed to have one particular aspect that stood out. With it being our most expensive bike in the shootout, there also isn’t much budget for upgrades, such as a more appropriate set of wheels.

Price: $2,499.99


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