Trek Fuel EX 9.8 XT Di2 Gen 7

Trek

Fuel EX9.8 XT Di2 Gen 7

Claimed weight15.08 kg / 33.25 lb (size M, with TLR sealant, no tubes)Complete bike
FrameOCLV Mountain Carbon fram…Fox Factory 36, Float EVOL…
GroupsetShimano XT Di2 M8250, 1…Shimano XT M8200, 12-spee…
WheelsBontrager Line Comp 30,…Maxxis Minion DHF, Tubeless…
Tire clearance64 mm

The seventh-generation Trek Fuel EX shifts away from its cross-country origins to become a decidedly aggressive, descending-biased trail bike. In its standard configuration, it pairs 145mm of rear suspension with a 150mm fork on dual 29-inch wheels. However, the defining characteristic of the Gen 7 platform is its modularity. By swapping rocker links and lower shock mounts, riders can reconfigure the chassis into a mixed-wheel MX setup or a long-travel LX enduro machine. This adaptability makes it highly versatile, but the core EX model is built for riders who prioritize downhill composure and technical traction over lightweight sprinting. Trek also updated the frame with a standard ZS headset, refined internal storage, and a straighter seat tube to accommodate longer dropper posts. It is a substantial, heavily built trail bike designed to survive rough terrain rather than dance lightly over it.

Trek Fuel EX
Build
Size
01 / Buy

Where to get it.

1 retailer · size M.

Size
1 retailer · Size M
02 / Specifications

Spec sheet.

Every component shipped with this build.

01Frameset
4 components
FrameOCLV Mountain Carbon frame with internal storage; ZS headset; adjustable leverage rate; guided internal routing; interchangeable alloy rocker link; interchangeable lower shock mount; downtube guard; shuttle guard; BSA 73; ISCG 05; ABP; UDH; Boost148; adaptable travel 145–160mm
Weight15.08 kg / 33.25 lb (size M, with TLR sealant, no tubes)
02Drivetrain & brakes
10 components
Shift leversShimano XT Di2 M8250, 12-speed
CranksetShimano XT 8200 crank, 30T, 55mm chainline, 170mm length
Bottom bracketShimano BB-MT501, BSA threaded
Front rotorShimano RT86, 6-bolt, 203mm
Rear rotorShimano RT86, 6-bolt, 180mm
04Cockpit & contact
5 components
StemBontrager Elite, 35mm clamp, 0°, 45mm length
SaddleVerse Short Pro, carbon rails, 145mm width
SeatpostBontrager Line Dropper, MaxFlow, internal routing, 34.9mm (S: 150mm travel/410mm length; M: 170mm/450mm; L–XXL: 200mm/515mm)
Grips/TapeTrek Line Elite, lock-on
03 / Geometry

Geometry & fit.

5 sizes published.

The Gen 7 geometry places the rider in a highly centralized, upright posture that heavily influences both climbing efficiency and descending control. Trek steepened the effective seat tube angle to nearly 78 degrees on some sizes, which prevents the rider's weight from cantilevering over the rear axle on steep pitches. This keeps the front wheel weighted and minimizes unwanted suspension sag during seated efforts.

At the front, a significantly taller stack height pairs with stock 40mm high-rise handlebars to create a commanding stance. This tall front end prevents riders from feeling pitched forward on steep roll-ins, encouraging an assertive, centered riding style.

A major structural update is the move to a straight, uninterrupted seat tube. This allows for massive dropper post insertion, with large and extra-large frames easily accommodating 200mm posts. The combination of the low bottom bracket, compact standover, and deep dropper insertion gives riders ample room to lean the bike aggressively through corners, offsetting some of the sluggishness that might otherwise come from its heavy chassis.

Reach × Stack · size Mmm

Where the handlebar sits relative to the bottom bracket — the single most important fit pair.

710669628586545STACK ↑385426468509550REACH →UPRIGHTLONG / LOWSize M460 · 624
01Fit geometry6 values
Stack624 mm
Reach460 mm
Top tube583 mm
Headtube length110 mm
Standover height742 mm
Seat tube length400 mm
02Component geometry5 values
Crank length170 mm
Handlebar width800 mm
Stem length45 mm
Saddle width145 mm
Dropper travel170 mm
03Handling geometry8 values
Headtube angle64.5°
Seat tube angle72.6°
BB height339 mm
BB drop35 mm
Trail129 mm
Offset44 mm
Wheelbase1225 mm
Chainstay length437 mm

Which size should I buy?

Slide your height to see the recommended size. GearWise's fit algorithm works from the published stack, reach, and ETT — the brand's own recommendation may differ.

Your height
5'8"173 cm
5'0"5'5"5'10"6'3"6'7"
Recommended sizeMBased on stack, reach & ETT for your height · score 89/100.

Calculated from GearWise's own stack / reach / ETT algorithm — the brand's size chart may recommend a different size, and a proper bike fit beats any calculator.

04 / Other builds

The lineup.

15 builds, ranging $2,300 – $8,500.

The Gen 7 Fuel EX lineup spans a wide price range, split between Alpha Platinum aluminum frames and OCLV Mountain Carbon options. The entry-level EX 5 provides a basic RockShox Recon fork and Shimano Deore drivetrain, but the alloy EX 8 is widely considered the value sweet spot. It pairs a Fox 36 Rhythm fork and Float X shock with SRAM's wireless Eagle 70 Transmission and DB8 four-piston brakes, offering high-end shifting reliability at a mid-tier price.

Moving into the carbon models, the 9.8 and 9.9 tiers introduce premium suspension, including Fox Factory Grip X2 or RockShox Lyrik Ultimate forks, alongside carbon wheels and handlebars. Drivetrain options at the upper end split between Shimano XT (mechanical or Di2) and SRAM's higher-tier Eagle 90 and X0 Transmissions. Braking also upgrades to SRAM Maven or Shimano XT four-piston calipers for increased stopping power. While the modular frame design allows riders to convert any EX build into an MX or LX configuration, doing so requires purchasing separate rocker links, lower shock mounts, and potentially new suspension components.

05 / Reviews

From the press.

6 reviews from the cycling press.

Reviewers consistently characterize the Gen 7 Fuel EX as a highly composed descender that masks its substantial weight with sophisticated suspension. The revised kinematics and Active Braking Pivot design provide excellent traction, keeping the rear wheel "glued to the ground" (Flow Mountain Bike) over rapid-fire hits and heavy braking. Testers found the initial suspension stroke offers a "useful, helpful, comfortable bit of ease" (Singletrackworld) that prevents the bike from feeling skittish on technical trails.

When pointed downhill, the bike's mass becomes an asset. The heavy frame delivers an "unshakeably anchored" (Mountain Bike Rider) sensation that mimics much larger gravity bikes, making it a "rocket on steep descents" (Cycling Magazine). However, that same weight creates noticeable inertia on flat terrain and out of slow corners. While it excels at technical, traction-limited climbing, testers noted it requires more effort to accelerate than lighter trail competitors.

The primary criticism across reviews centers on the stock Bontrager Brevard tires, which testers found too flimsy for the bike's aggressive capabilities, frequently suffering punctures. Additionally, some reviewers experienced cable rattle on the alloy frames and an internal rattle on the Fox 36 Rhythm fork equipped on the EX 8 build.

06 / Compared to

Compared to.

Most-viewed comparisons.