The Trek Fuel EX 9.9 29 had a lot to lose, as it was defending its title in this comparison. In our last group test, the bike secured the coveted top spot. Since then, Trek has fundamentally reworked the shock – was it enough to win again?

For an overview head to the main article: Everyday Heroes! – We review six of the hottest, grin-inducing trail bikes

Trek Fuel EX 9.9 29 | 130/130 mm (f/r) | 12.15 kg | € 7,999

At first glance, nothing has changed on the Trek Fuel EX 9.9 29 compared to the previous year (except for the paint job). The biggest innovation is hidden from the naked eye in the rear FOX shock. It is called Thru Shaft technology and is a completely different damping concept. While classic shocks pressurise oil in an internal chamber to compensate for the decreased volume caused by the piston’s compression, Thru Shaft allows the piston to move through the shock. The absence of pressure reduces the breakaway torque and leads to a more sensitive response. On the new model, Trek has also replaced the DT Swiss XMC 1200 carbon rims with their in-house Bontrager Line Pro 30 OCLV Carbon. The rest of the components remain almost unchanged and consist of a SRAM X01 Eagle drivetrain, a FOX Factory fork with 130 mm travel, and other Bontrager parts. Unfortunately, the 125 mm adjustment range of the Drop Line dropper seatpost isn’t quite enough and, on top of that, the post rattles when fully inserted.

The suspension of the Fuel EX 9.9 29 is very plush. The seating position is good – assuming your legs are not overly long. If they are, it’s worthwhile to push the saddle forward so as not to sit too far behind the rear wheel. The rear suspension remains relatively composed even with the platform damping open. When pedalling seated, however, it’s recommended to make use of the lockout lever. Completely locking out the rear shock turns the Fuel EX into a capable sprinter. Despite only 130 mm of travel, the rear end feels very plush on the downhills and swallows even the biggest of chunks with ease. The 130 mm FOX 34 in front can only partially keep up.

  Ride comfort 2.0! The Trek Fuel EX is our first choice for long rides!

However, the suspension harmonises very well on flowing trails. Only when the terrain became challenging, steep, and fast did we wish for a little more travel at the front. (We are sure that a 140 or 150 mm fork would extend the range of application of the Fuel EX enormously.) As it is, the bike rides calmly and is very easy to manoeuvre. Riding the bike, you’re securely integrated between the large 29″ wheels, always feeling in control. Overall, the Fuel is a lot of fun to ride and convinced us with its high degree of agility!

Helmet Giro Montaro Jersey ENDURO Jersey | Shorts Maloja KampenwandM | Backpack Deuter Trans Alpine 24

The Trek Fuel EX 9.9 29 in detail

Fork FOX 34 Factory Float 130 mm
Rear shock FOX Float Factory RE:AKTIV Thru Shaft 130 mm
Brakes SRAM Guide Ultimate
Drivetrain SRAM X01 Eagle
Seatpost Bontrager Drop Line 125 mm
Stem Bontrager Line Pro 35 60 mm
Handlebar Bontrager Line Pro 750 mm
Tires Bontrager XR4 Team Issue
Wheelset Bontrager Line Pro 30 OCLV Carbon
Weight 12.15 kg
Price € 7,999

Knocked out
The Knock Block prevents the fork from hitting the down tube and protects the frame.
The geometry adjustment on the Trek Fuel EX is fiddly to use and takes some time, so we never used it. A slightly steeper seat angle would make it completely superfluous.
Unfortunately, the Bontrager dropper seat post does not do the Fuel EX justice. It doesn’t offer enough adjustment and rattles annoyingly on downhills.
With Thru Shaft Technology, the piston moves through the shock. This technology isn’t entirely new. There have been forks with this system, though they’ve disappeared from the market. Now Trek is making another attempt.

Geometry of the Trek Fuel EX

Size XS S M L XL
Seat tube 394 mm 419 mm 440 mm 470 mm 510 mm
Top tube (effective) 543 mm 578 mm 595 mm 610 mm 636 mm
Head tube 100 mm 100 mm 100 mm 100 mm 110 mm
Head angle 67.7° 67.7° 67.7° 67.7° 67.7°
Seat angle (effective) 74.7° 74.7° 74.7° 74.7° 74.7°
Chainstay 432 mm 432 mm 432 mm 432 mm 432 mm
BB Height 30 mm 30 mm 30 mm 30 mm 30 mm
Wheelbase 1,121 mm 1,156 mm 1,173 mm 1,188 mm 1,214 mm
Reach 399 mm 433 mm 450 mm 465 mm 487 mm
Stack 603 mm 603 mm 603 mm 603 mm 612 mm


The Trek Fuel EX 9.9 29 is better than ever! The rear end works superbly and filters away every irregularity, all with only 130 mm of travel; if you’re looking for a supremely comfortable bike to take on long rides, be sure to put the Trek Fuel EX on your shortlist. The only thing we missed was a more potent, longer-travel fork.


– the rear suspension is amazing
– well-behaved handling
– a true all-rounder for long rides


– short-travel fork limits the potential of the bike
– dropper seatpost hasn’t got enough stroke

Value for money

More info at:

The test fleet

For an overview head to the main article: Everyday Heroes! – We review six of the hottest, grin-inducing trail bikes

All bikes in test: Giant Trance Advanced 0 | Liteville 301 MK14 All Mountain | Nicolai ION-G13 QLFLINE | Scott Genius 700 Ultimate | Specialized S-Works Stumpjumper 29

This article is from ENDURO issue #031

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