The latest rendition of a true classic. With the Fuel EX 9.9 X0 AXS T-Type, the American manufacturer introduces the latest generation of their trail veteran, which is intended to cover an even wider range of applications, and can be perfectly adapted to your needs with many adjustment options. How does the concept work in practice?
14.9 kg in size L | € 9,499 | Manufacturer’s website
The Trek Fuel EX 9.9 X0 AXS T-Type was conceived as a potent trail bike with a top-tier spec. It generates more travel than its predecessor, combining 150/140 mm at the front and rear, respectively. Retailing at € 9,499, the Fuel EX tips the scales at 14.9 kg and looks a lot like its electric counterpart, the Fuel EXe, which has already proven what it’s capable of in our light eMTB comparison test. The analogue Fuel EX model is available in seven sizes and offers countless adjustment options, both for the geometry and kinematics, making it an incredibly versatile bike.
For an overview of the test fleet head to the group test: The best trail bike 2024 – 15 of the most exciting trail bikes in our 2024 comparison test
The 2023 Trek Fuel EX 9.9 X0 AXS T-Type in detail
With its unmistakable frame silhouette and vertically-mounted shock, the Fuel EX 9.9 X0 AXS T-Type is distinctly recognisable as a Trek. The proprietary Active Braking Pivot rear suspension positions the rear axle inside the rear pivot bearing, which is meant to reduce the impact of braking on suspension performance. As usual, the cables are routed internally, running through the frame inside a sleeve, which makes it easier to work on the bike and replace the cables. The cables aren’t clamped at the ports, but don’t rattle on the trail. However, the brake line of the rear SRAM CODE Stealth brake slams against the handlebars and can’t be secured to the one-piece handlebar. A generously sized TPU plate on the down tube protects the frame against impacts and is complemented by an extensive chainstay protector. That said, when landing big drops and ploughing through rough trail sections, you can still hear the chain slapping against the frame. Of course, there’s also a storage compartment in the down tube – Trek were amongst the pioneers of on-bike stowage systems! The closure system is easy to use and seals tightly. The storage compartment comes standard with a small pouch where you can securely store all your trail essentials . Trek also hide a Bontrager multi-tool inside the steerer tube, which includes all of the basic tools for essential trailside repairs. Unfortunately, the tool makes a faint rattling noise on the trail, and while it’s not too bad, you still know that it’s there.
The spec of the 2023 Trek Fuel EX 9.9 X0 AXS T-Type
The Fuel EX 9.9 X0 AXS T-Type might not be the flagship model in the Fuel EX range, but it has a top spec. The FOX Factory suspension consists of a 36 mm GRIP2 fork and standard FLOAT X shock, which supercedes Trek’s proprietary Thru Shaft shock found on older previous models. The cables are routed internally, and run through the frame inside guide sleeves, which makes it easier to service the bike and replace the cables. The wireless, 170 mm RockShox Reverb AXS dropper post ensures lightning fast, butter smooth action. The American component colossus also supplies the CODE Silver Stealth brakes with tool-free bite point and lever reach adjustments. The levers also feature SRAM’s proprietary SwingLink technology, which was designed to minimise deadband and optimise modulation, thus reducing arm pump. The brakes are effectively identical to the Ultimate flagship model except for the carbon levers, and paired with a 200 mm rotor at the front and 180 mm disc at the rear. We would recommend upgrading to a 200 rotor at the rear to improve braking performance and modulation. The SRAM X0 Transmission rear derailleur is attached directly to the frame, forgoing both a mech hanger and the limit screws. Trek’s in-house, one-piece Bontrager RSL one-piece carbon cockpit consists of a 50 mm stem and 820 mm handlebars. These are far too wide, so we recommend cutting them to size. Moreover, the one-piece design doesn’t allow for fine tuning, except for the stack height, which can be adjusted with conventional round spacers – the cockpit on the SCOTT doesn’t even allow you to do that, with its proprietary spacers. The Fuel EX rolls on a Bontrager Line Pro 30 wheelset and Bontrager SE5 Team Issue tires front and rear, which are a perfect match for the bike’s intended use, providing predictable, controlled handling and adequate puncture protection.
How would you like it? The Trek is available in countless frame sizes and offers many adjustment options.
The storage compartment is nothing new for Trek, but still works flawlessly.
The Mino Link is a flip chip in the seat stay that lets you switch between a high and low geometry setting.
With the FOX FLOAT X, Trek finally replaced their proprietary Thru Shaft shock with a standard model.
At 820mm, the Bontrager RSL one-piece cockpit is far too wide. By shortening the carbon handlebars, however, you’ll inevitably increase the cockpit’s stiffness.
The mini tool in the steerer tube allows you to carry out all basic trailside repairs, but rattles slightly on rougher trails.
Trek Fuel EX 9.9 X0 AXS T-Type
€ 9,499
Specifications
Fork FOX 36 Factory GRIP2 150 mm
Rear Shock FOX FLOAT X Factory 140 mm
Seatpost RockShox Reverb AXS 170 mm
Brakes SRAM CODE Silver Stealth 200/180 mm
Drivetrain SRAM X0 Transmission 1x12
Stem Bontrager RSL 50 mm
Handlebar Bontrager RSL Onepiece Carbon 820 mm
Wheelset Bontrager Line Pro 30 Carbon 29"
Tires Bontrager SE5 Team Issue/Bontrager SE5 Team Issue 2.5"/2.5"
Technical Data
Size XS S M ML L XL XXL
Weight 14.9 kg
Specific Features
Tool in headset
storage compartment
Flip-Chip
Tuning tips: Shorten the carbon handlebars, though this will result in a stiffer cockpit | Upgrade to a bigger 200 mm rotor at the rear
Pants Alpinestars Stella Drop Algorithm | Shoes Crankbrothers Mallet Speedlace
The geometry of the 2023 Trek Fuel EX
The Trek Fuel EX is available in a whopping seven, sizes XS to XXL, which includes an intermediate ML size. Reach values change in smaller intervals between sizes M, ML and L, which makes it easier to choose your frame size if you’re sitting on the fence. The smallest XS frame rolls on 27.5″ wheels and with size S you can choose between 27.5″ and 29″, while all other frames come standard with 29” wheels. The Fuel EX also features three different geometry adjustments: the Mino Link, which is essentially a flip chip in the seat stay, lets you switch between a high and a low setting. Another flip chip in the lower shock mount changes the rear suspension’s progression, making it compatible with a coil shock. Moreover, you can change the head tube angle between three different settings using different headset cups that can be purchased separately. If you fancy a mullet bike, the Fuel EX is a great option, as it can be converted to a mixed-wheel setup using a 160 mm fork and the low geometry setting. We mainly rode the bike in the low setting, with progressive rear suspension. Chainstay length is a moderate 440 mm in size L and grows with the frame size, with four different lengths serving the 7 different frame sizes.
| Size | XS | S | M | ML | L | XL | XXL |
|---|---|---|---|---|---|---|---|
| Top tube | 516 mm | 551 mm | 584 mm | 607 mm | 627 mm | 662 mm | 697 mm |
| Seat tube | 360 mm | 380 mm | 410 mm | 420 mm | 435 mm | 470 mm | 500 mm |
| Head tube | 95 mm | 95 mm | 100 mm | 100 mm | 105 mm | 120 mm | 135 mm |
| Head angle | 64.5° | 64.5° | 64.5° | 64.5° | 64.5° | 64.5° | 64.5° |
| Seat angle | 75.8° | 75.8° | 75.8° | 75.8° | 75.8° | 75.8° | 75.8° |
| Chainstays | 435 mm | 435 mm | 435 mm | 440 mm | 440 mm | 445 mm | 445 mm |
| BB Drop | 25 mm | 25 mm | 38 mm | 38 mm | 38 mm | 38 mm | 38 mm |
| Wheelbase | 1,145 mm | 1,175 mm | 1,213 mm | 1,233 mm | 1,250 mm | 1,287 mm | 1,323 mm |
| Reach | 400 mm | 430 mm | 450 mm | 470 mm | 485 mm | 515 mm | 545 mm |
| Stack | 574 mm | 574 mm | 617 mm | 617 mm | 621 mm | 635 mm | 648 mm |
The 2023 Trek Fuel EX 9.9 X0 AXS T-Type on the trail
When riding uphill, the Trek Fuel EX 9.9 X0 AXS T-Type places you in a comfortable, upright pedalling position, with the weight evenly distributed between the front and rear. However, on steep climbs, the front end becomes a little light, forcing you to actively weight the front wheel to keep it tracking. The suspension bobs noticeably, and as a result, climbs are more of a means to an end for the Trek, which doesn’t feel as lively as some of its competitors. On long, monotonous climbs, we recommend reaching for the climb switch to kill the pogo stick effect and get to the trailhead more efficiently.
On the trail, the Fuel EX impresses with predictable, balanced handling and strikes an excellent balance between agility and composure.
When gravity takes over, the Trek Fuel EX makes you feel at ease from the get-go, responding to steering inputs eagerly without feeling too nervous. The suspension is one of the Fuel EX’s true strengths, working discreetly in the background while simultaneously doing exactly what you want it to, without any unpleasant surprises. Even in the progressive setting with an air shock, the suspension responds sensitively and generates good traction, while at the same time providing plenty of support in the mid-stroke, allowing you to generate speed by pumping through flow trails and providing enough reserves to bail you out of botched landings without bottoming out. All in all, the Trek is very composed, providing a similar degree of stability as the Santa Cruz and Cannondale – though struggling to keep up with them in terms of agility. This becomes evident particularly in tight corners, where the Trek feels a little cumbersome – shortening the handlebars would help significantly here. Nevertheless, the Fuel EX is a strong all-rounder that performs well on a variety of trails and strikes a great balance between agility and composure.
Who should take a closer look at the 2023 Trek Fuel EX 9.9 X0 AXS T-Type?
The intuitive handling and excellent rear suspension make the Trek Fuel EX 9.9 X0 AXS T-Type suitable for a wide range of trails and riders. With its many geometry and kinematics adjustments, it’s also a good choice for those riders who love to play around with different setups to find their sweet spot. It’s easy and intuitive to ride, and delivers outstanding trail performance, whether you’re a beginner or seasoned trail veteran. The harmonious overall package is rounded off with clever frame details, like the well-designed storage compartment and integrated minitool.
Our conclusions about about the 2023 Trek Fuel EX 9.9 X0 AXS T-Type
A perfect fit! With the Fuel EX 9.9 X0 AXS T-Type, Trek have created a bike for all tastes with clever frame features and countless adjustment options. It’s a strong all-rounder with easy, intuitive handling that strikes an excellent balance between agility and composure. The suspension works discreetly in the background but is sensibly tuned, showing no real weaknesses. Together with the consistently high-quality spec, this makes the Fuel EX a faithful companion for all kinds of trails.
Tops
- Excellent balance between agility and composure
- Suspension works discreetly in the background but delivers a tremendous performance
- Clever frame details
Flops
- Handling slightly cumbersome
- Handlebars too wide
You can find out more about at trekbikes.com
The test field
For an overview of the test fleet head to the group test: The best trail bike 2024 – 15 of the most exciting trail bikes in our 2024 comparison test
All bikes in test: Cannondale Habit LT 1 (Click for review) | Cube ONE55 C:62 SLT 29 (Click for review) | Ghost RIOT Trail Full Party (Click for review) | Merida ONE-FORTY 10K (Click for review) | Mondraker Neat RR SL (Click for review) | Nicolai Saturn 14 Swift HRZ (Click for review) | Orbea Occam LT M10 (Click for review) | Santa Cruz Heckler SL XX AXS RSV (Click for review) | Santa Cruz Hightower X0 AXS RSV (Click for review) | Scor 2030 X01 (Click for review) | SCOTT Genius ST 900 Tuned (Click for review) | Specialized S-Works Turbo Levo SL (Click for review) | Trek Fuel EX 9.9 X0 AXS T-Type | Yeti SB140 LR T3 X0 (Click for review) | YT JEFFSY CORE 5 CF (Click for review)
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Words: Simon Kohler Photos: Peter Walker
