Issue #042, Review - February 4, 2020

Trek Fuel EX 9.9 X01 AXS Project One on test – one bike, endless possibilities!

The Trek Fuel EX 9.9 is a classic in the trail bike segment. Last year, Trek completely redesigned the bike, putting a storage compartment in the down tube, updating the geometry and revising the suspension. We’ll tell you whether the new Fuel EX can build on the success of its predecessor.

Click here for an overview of the best trail bike in test.

If you’ve got a big enough budget, you can create your very own Fuel EX dream bike thanks to Trek’s Project One program. The customisation available for the paint job is almost limitless and there are some very fancy finishes to choose from. Our favourite is undoubtedly the ICON/Refliptive option. Trek have increased the travel of the Fuel EX and the 29er now offers 140 mm up front and 130 mm on the rear. The latter is controlled by a FOX 36 Factory fork with a GRIP2 damper and a specially developed RockShox Deluxe RT3 shock with RE:aktiv damping and Thru Shaft technology. The shock design, exclusive to Trek, sees the whole piston rod move through the body of the shock when compressed, making an IFP (internal floating piston) to compensate for volume changes when the shock compresses unnecessary. Without the additional seals of an IFP, which add friction, the shock should respond more sensitively and react more quickly to impacts. The rest of the componentry of the € 9,099 Project One bike leaves little to be desired. The SRAM AXS components and Shimano XTR four-piston brakes are tried and tested. The only two things we would have changed are a longer dropper post to replace the standard 150 mm version and grippier tires. The 2.6” Bontrager XR4 tires couldn’t convince us and should be swapped before you leave the shop. We were also annoyed by the chain constantly slapping the chainstay when riding in a hard gear.

Trek Fuel EX 9.9 X01 AXS Project ONE

€ 9,099

Specifications

Fork FOX 36 FLOAT Factory GRIP2
Rear Shock FOX Float RE:aktiv Thru Shaft
Seatpost RockShox Reverb AXS 150 mm
Brakes Shimano XTR M9120 (Serie XT) 200/180 mm
Drivetrain SRAM X01 Eagle AXS 32/10-50
Stem Bontrager Line Pro 50
Handlebar Bontrager Line Pro 780 mm
Wheelset Bontrager Carbon 30
Tires Bontrager XR4-Team Issue 120 TPI 120 2,6

Technical Data

Size XS S M L XL
Weight 13,08 kg
Wheelsize 29"
Travel (f/r) 140/130 mm

**Firm and direct**
Despite complex technology in the shock, the rear end of the Fuel EX isn’t the plushest or most sensitive. Instead, it’s rather firm and defined

**Undefined**
The Bontrager XR4 Team Issue tires couldn’t deliver. They offer little grip and slide uncontrollably over the entire tread. We would recommend fitting something with more aggressive shoulder knobs.

**Excellent choice**
Up until a few years ago, a 140 mm trail bike would have come with a FOX 34 fork. It is all the better to see that Trek have chosen to fit a FOX 36 with a GRIP2 damper – excellent!

**Practical, but small**
The storage compartment in the down tube on the Trek offers space for a tube and tools and is super easy to open. Unfortunately, the opening is very small – compared to Specialized’s SWAT box, getting stuff in and out is a fumble.

**Unnecessary**
We didn’t use the flip chip and although the steeper seat tube angle would have been nice on the climbs, we preferred the slacker setting for the descents. In practice, changing it back and forth is too much of a hassle.

**Top class**
The paint effect combined with matt black elements is just one of many possibilities with Trek’s Project One configurator

Geometry of the Trek Fuel EX 9.9

Trek have never been known for extreme geometry and the Fuel EX doesn’t buck that trend. The 470 mm reach in size L is just right, the head angle is not particularly slack at 66° and the 75° seat tube angle is rather conservative. On top of that, the effective seat tube angle slackensas you extend the dropper post due to the bend in the seat tube. Like the Slash, the Fuel EX features the Mino Link flip chip to adjust the geometry, but we always left it in the slacker setting.

With Trek’s Project One program, there are almost no limits to your own creativity – if you’re dreaming of a custom paint job, this is what you need!

Size	XS 27,5″	S 27,5″	S 29″	M 29″	ML 29″	L 29″	XL 29″	XXL 29″
Seat tube	356 mm	395 mm	395 mm	420 mm	435 mm	450 mm	500 mm	540 mm
Top tube	546 mm	568 mm	578 mm	603 mm	619 mm	634 mm	663 mm	688 mm
Head tube	90 mm	100 mm	100 mm	100 mm	105 mm	105 mm	105 mm	140 mm
Head angle	66°	66°	66°	66°	66°	66°	66°	66°
Seat angle	75°	75°	75°	75°	75°	75°	75°	75°
Chainstays	437 mm	437 mm	437 mm	437 mm	437 mm	437 mm	437 mm	437 mm
BB–Offset	43 mm	43 mm	43 mm	43 mm	43 mm	43 mm	43 mm	43 mm
Wheelbase	1.120 mm	1.144 mm	1.154 mm	1.179 mm	1.196 mm	1.211 mm	1.242 mm	1.270 mm
Reach	395 mm	415 mm	415 mm	440 mm	455 mm	470 mm	495 mm	515 mm
Stack	563 mm	572 mm	608 mm	608 mm	613 mm	613 mm	627 mm	645 mm

The Fuel EX on test

The Fuel EX gives you that typical Trek feeling right from the start. The riding position is slightly stretched due to the slack seat tube angle and the front is low. This is perfect for going fast on level terrain. However, you should push the saddle forward if you’re going to tackle steep climbs. Thanks to the firm suspension and light wheels, the Fuel EX accelerates very willingly and conserves your energy on long rides. Light-footed as it is, the bike masters technical climbs with ease, but the Bontrager tires lack grip on wet roots.

The Fuel EX is a super versatile bike – efficient on the climbs and balanced on the descents!

The tires also leave the bike struggling on the descents. As this put it far behind the competition, we tested the Fuel EX with different tires fitted. The position on the bike is central and the handling is super intuitive. This makes the Trek an easy bike to ride fast. Changing direction is quick and easy and the bike motivates you to manual or catch air as soon as you hit a roller or lip. The agile handling only becomes a disadvantage in really rough terrain where it takes a strong rider to keep the bike on course. At high speeds, the firm suspension doesn’t help here either and despite the Thru Shaft technology in the shock, the rear doesn’t respond as sensitively as the best bikes in the test.

Tuning tip: swap the tires | push the saddle forward | better chainstay protector

**Helmet** 100% Altec | **Glasses** Oakley Jawbreaker | **Shirt** Fox Ranger | **Short** Short POC Resistance Enduro Light Shorts | **Kneepads** Fox Launch Pro | **Hip Bag** USWE Zulo 2l

How does the Fuel EX compare to the competition?

The firm character of the Trek Fuel EX is not unlike the Norco Optic C1, though the Trek does offer more comfort overall. Aggressive riders are better off with the Norco due to the added support of the suspension and more progressive geometry. Relaxed riders, on the other hand, will find a more versatile and good-natured bike in the Trek.

Riding Characteristics

Uphill

sluggish
efficient

Agility

cumbersome
playful

Stability

nervous
confident

Handling

demanding
balanced

Suspension

harsh
plush

Fun Factor

planted
poppy

Value for money

terrible
very good

Intended Use

XC

Trail

Enduro

Downhill

Conclusion of the Trek Fuel EX

The Trek Fuel EX is a great all-rounder that offers very intuitive and good-natured handling. It’s a very efficient and playful bike, but it lacks composure in demanding terrain. If you’re looking for one bike to do it all, this is it – as long as you fit different tires.

Tops

light-footed and efficient climber
intuitive, good-natured and fun handling
storage compartment in the down tube for tools or food

Flops

not the most sensitive rear end
tires lack grip
chain slap

For more information head to trekbikes.com

The test field