Evolution of the all-round trail bike: The new Trek Fuel EX on test
In this article, we use so-called affiliate links. With every purchase through these links, we receive a commission from the merchant. All relevant referral links are marked with . Learn more.
The frame of the new Fuel EX is a consistent further development of the popular trail bike. The reach has been extended by around 20 mm across all sizes. The head angle has been slackened from 66 degrees to 64.5 degrees and the seat angle has been steepened by around 2 degrees. The rear suspension travel has been increased to 140mm.
Like other manufacturers, Trek also rely on size-specific chainstay lengths for the new Fuel EX. However, all sizes of one wheel size use the same chainstay and achieve the change in length by connecting the chainstay to the main frame. In size XS, the bike is only available with 27.5 inch wheels, in size S with 27.5 or 29 inch wheels. All other sizes are only available as 29ers. If you want to ride the Fuel EX as a mullet, you will need a fork with 160 mm travel in addition to the 27.5 inch rear wheel.
With the Mino-Link you can change the steering angle by 0.5 degrees and the height of the bottom bracket by 8 mm. If that's not enough, you can also adjust the steering angle by +/- 1 degree without affecting the bottom bracket height with the help of separately available angle headset shells. Trek offers a geometry calculator on its website so that you don't lose track of all the possibilities.
Details and customisation options on the Trek Fuel EX
In addition to the revised geometry, the new frame offers a number of practical details. The storage compartment in the down tube, which was previously reserved for the carbon models, is now also available on the aluminium models. The down tube protection consists of two parts and can be screwed on or off as required.
To provide more stability for long dropper posts, the new Trek Fuel EX uses a 34.9 mm seat tube. Depending on the size and frame material, the maximum insertion depth is between 180 mm (XS, aluminium) and 330 mm (XXL, aluminium). Furthermore, the internal cable routing is fully routed, which, in combination with the BSA bottom bracket, increases ease of maintenance. There is also an ISCG-05 mount for chain guides and bashguards.
The progression of the rear triangle can be adjusted with a flip chip, for example to use a coil shock.
The Trek Fuel EX has something for everyone
The most favourable version of the Fuel EX is the Fuel EX 5, although it still relies on the old frame. For MTB newcomers, the Fuel EX5 with a Deore 12-speed drivetrain, Rockshox Recon fork and X-Fusion shock offers a solid introduction to the sport.
The EX 7 is the entry-level model for the new Trek Fuel EX with a Rockshox 35 Gold fork, Fox Performance Float shock and a shifting mix of Shimano SLX and XT. Braking is provided by groupless Shimano brakes. The top model of the aluminium frames is the Fuel EX 8 with a Fox Rythm 36 fork, complete Shimano XT drivetrain and Deore 4-piston brakes.
The cheapest carbon model is the Fuel EX 9.7, which, like the EX 8, relies on the Rythm 36 suspension fork and Deore brakes, but only gets a shifting mix of SLX and XT. The top Fuel EX 9.9 models rely on a complete Fox Factory suspension system and Bontrager carbon rims. The Fuel EX 9.9 is available with full Shimano XTR equipment or with XX1 AXS groupset and Code RSC brakes.
All bikes except the EX 5 come with complete tubeless accessories. The new Trek Fuel EX will also be available in Project One.
In the field test: Trek Fuel EX 9.9 AXS
With the consistent further development of the new Fuel EX, Trek is right on trend. Compared to its predecessor, more suspension travel, a longer reach and larger chainstay lengths should pay off, especially in terms of downhill performance. Hardly any other all-mountain bike offers so many customisation options - it's a good thing that Trek provides an online geometry calculator for this purpose. With a flip-chip in the Mino-Link, interchangeable angled headset shells and an optional mullet structure, this helps you keep track of everything. An adjustable shock mount also allows the rear triangle progression to be adjusted. In the 9.9 model version, the Americans reach right to the top of the equipment shelf and drive the price up to a dizzying 13,500 euros.
Thanks to the long wheelbase and slack steering angle, the Trek rides downhill like it's on rails. Experienced riders can reach high speeds when travelling straight ahead and in long bends. Together with powerful brakes and grippy tyres, this quickly creates a race feeling. The suspension of the Trek Fuel EX is sensitive on the trail and never lacks support. Unfortunately, a defective damping cartridge in the Fox Factory fork spoilt the picture of the outstanding spec. The downside of the long geometry becomes apparent on tight singletrack. Here, the length makes for unwieldy handling. We also missed some manoeuvrability and playfulness on flat trails.
The Fuel EX 9.9 pedals very efficiently uphill thanks to the steep seat angle. The bobbing of the rear suspension can be eliminated with the effective platform lever. The
The high weight does not reflect the price.
Summary by Jan Timmermann, BIKE volunteer:
Maximum adjustment options and useful details make the
Trek Fuel EX particularly exciting for tech freaks. On the trail, the long and versatile bike craves speed. The price tag is pure madness despite the high-end equipment.
Technical data and grades of the Trek Fuel EX 9.9 AXS
Manufacturer information
- Price: 13499 Euro
- available from specialised dealers
- Material / Size: Carbon XS / S / M / L / XL (47 cm, tested)
Measured values
- Weight without pedals: 14.38 kg
- Frame weight without shock: 2801 g
- Weight of wheels: 5094 g
- Acceleration of running wheels: 4259 kg x cm²
- Handlebar width: 820 mm
- Frame rigidity (absolute): 30 N/mm
Equipment
- Wheels: Bontrager Line Pro 30
- Tyres: Bontrager SE 5 Team Issue 29 x 2.50
- Fork: Fox Float 36 Factory Grip 2
- Shock: Fox Float X Factory
- Front / rear suspension travel: 150 / 140 mm
- Brakes: Sram Code RSC 200 mm / 180 mm
- Gear system:: Sram XX1 Eagle AXS 1 x 12
- Gear ratio / belt width:. 32; 10-52 / 520 %
- Tele support: Rockshox Reverb AXS / 170 mm
Valuation
- Driving behaviour uphill: 21.25 from 25
- Chassis efficiency: 13 out of 20
- Rolling resistance: 7.5 out of 10
- Weight: 4.5 out of 15
- Inertia impellers 4 of 10
- Bottle cage : 7 from 10
- Driving behaviour downhill: 31.5 from 35
- Rear suspension: 21.25 out of 25
- Front suspension: 18 out of 20
- Retractability: Saddle 10 out of 10
- Brakes: 14.25 out of 15
- Tyre grip:: 12.75 out of 15
- Driving stability: 4 out of 10
- Total uphill: 57.25 out of 90
- Total downhill: 111.8 of 130
- Other: 26.25 out of 30
- Ease of maintenance: good
BIKE test rating: very good - 195.3 out of 250 points
The BIKE judgement reflects the laboratory measurements and the subjective impression of the test riders. The BIKE judgement is independent of price.
BIKE judgements: super (250-205 P.), very good (204.75-170 P.), good (169.75-140 P.), satisfactory (139.75-100 P.), with weaknesses, unsatisfactory. ²Price may be subject to additional costs for packaging, shipping and coordination.
Jan Timmermann
Editor
