Inspection
Frame condition
Inspect the frame, fork, welds, and high-stress areas for cracks, dents, or prior repairs.
Trek
2021 Trek Fuel EX 9.9 X01
Previous used estimate
$2,889 - $2,972
Actual value depends on condition, size, and local demand.
Value Guide market data · 2021 Trek Fuel EX 9.9 X01
12-month projected trend
13%
Direction and magnitude, not judgment
vs. category average
5%
Drops faster than category avg
Price over time - 2021 Trek Fuel EX 9.9 X01
Values based on actual sales data. Enter your bike's specifics to get a precise valuation.
All Fuel model years
Overview
About this bike
Fuel EX 9.9 makes no compromises. Top-shelf suspension, carbon everything, and SRAM's latest X01 Eagle drivetrain make this ripper ready to rule any trail in style. It's fast, it's light, and it's got everything you need to crush your next trail ride. It's right for you if... You want a bike as versatile as you are, and you're demanding—of yourself and of your equipment. You want the lightest weight, the most adjustability, and the highest precision so the last thing you have to worry about on your next adventure is your bike. The tech you get A light and stiff OCLV Mountain Carbon frame with internal storage, FOX Factory suspension with Kashima Coat and an efficient yet plush RE:aktiv with Thru Shaft damper. Plus, SRAM's latest X01 Eagle drivetrain with a huge 52-tooth cog and Bontrager carbon wheels and a whole bunch of other carbon parts for lower weight and elevated good looks. The final word If you can have just one mountain bike, this is it. Fuel EX 9.9 has the lightest parts with the most adjustability and precision. It's equally at home on fast flowy singletrack, brutal leg-busting climbs, and gnarly arm-pumping descents. Why you'll love it - Fuel EX 9.9 is for riders who want the best in everything. It's dripping with carbon and has the latest in suspension and drivetrain tech - RE:aktiv with Thru Shaft works faster than a normal shock, so it tracks the ground better and keeps you in control - The Fox Factory 36 fork gives you four-way damping adjustments, plus you get Kashima Coat for smoother, more durable stanchions - We expanded our size range to ensure a better fit for all riders. And, you get the fastest wheel that fits your frame: XS frames get 27.5" wheels, S frames get to choose between 27.5" or 29", and sizes M to XL get 29" wheels - Make it yours: it's fully customizable through Project One Wheel size: Sizes X-Small – Small: 27.5-inch Sizes Small – X-Large: 29-inch
Specifications
- Subtype
- Trail / Enduro
- Category
- Mountain
- Component Fork
- Fox Factory 36, Float EVOL air spring, GRIP2 damper, tapered steerer, 44mm offset, 15mm Kabolt axle, 140mm travel
- Component Size
- X-Small, Small, Medium, Medium/Large, Large, X-Large
- Component Stem
- Bontrager Line Pro, 35mm, Knock Block, Blendr compatible, 0 degree
- Product Family
- Fuel
- Component Axles
- Front: 110 x 15mm thru-axle Rear: 148 x 12mm thru-axle
- Component Chain
- SRAM GX Eagle, 12 speed
- Component Color
- Lithium Grey/Factory Orange, Raw Carbon/Rage Red, Matte Carbon Smoke
- Component Frame
- OCLV Mountain Carbon main frame & stays, internal storage, tapered head tube, Knock Block, Control Freak internal routing, Carbon Armor, ISCG 05, magnesium rocker link, Mino Link, ABP, 130mm travel
- Component Brakes
- SRAM G2 RSC 4-piston hydraulic disc w/SRAM CenterLine, 6-bolt, round-edge rotors
- Component Pedals
- Sold separately
- Component Saddle
- Bontrager Arvada Pro, carbon rails, 138mm width
- Component Headset
- Knock Block Integrated, 58-degree radius, cartridge bearing, 1-1/8'' top, 1.5'' bottom
- Component Cassette
- SRAM Eagle XG-1275, 10-52, 12 speed
- Component Crankset
- SRAM X01 Eagle carbon, DUB, Boost (52mm chainline)
- Component Shifters
- SRAM X01 Eagle, 12 speed
- Component Handlebar
- Bontrager Line Pro, OCLV Carbon, 35mm, 27.5mm rise, 780mm width
- Component Seat Post
- Bontrager Line Elite Dropper, 100mm travel, internal routing, 31.6mm; XS – S: 100mm travel / M – ML: 150mm travel / L – XL: 170mm travel
- Component Chainrings
- 30T alloy ring
- Component Front Tire
- Bontrager XR4 Team Issue, Tubeless Ready, Inner Strength sidewall, aramid bead, 120 TPI, 2.60 / 2.40"
- Component Rear Shock
- Fox Factory Float EVOL, RE:aktiv with Thru Shaft 3-position damper, Kashima Coat, tuned by Trek Suspension Lab; XS – S: 210x52.5mm / M – XL: 210x55mm
- Component Tape Grips
- Bontrager XR Trail Elite, alloy lock-on
- Component Wheel Size
- 27.5-inch, 29-inch
- Component Bottom Bracket
- SRAM DUB, 92mm, PressFit
- Component Rear Derailleur
- SRAM X01 Eagle
- Component Accessories Extras
- Bontrager BITS Internal Frame Storage Bag
- Rear Shock
- Fox Factory Float EVOL, RE:aktiv with Thru Shaft 3-position damper, Kashima Coat, tuned by Trek Suspension Lab; XS – S: 210x52.5mm / M – XL: 210x55mm
- Crankset
- SRAM X01 Eagle carbon, DUB, Boost (52mm chainline)
- Pedals
- Sold separately
- Bottom Bracket
- SRAM DUB, 92mm, PressFit
- Chain
- SRAM GX Eagle, 12 speed
- Saddle
- Bontrager Arvada Pro, carbon rails, 138mm width
- Handlebar
- Bontrager Line Pro, OCLV Carbon, 35mm, 27.5mm rise, 780mm width
- Headset
- Knock Block Integrated, 58-degree radius, cartridge bearing, 1-1/8'' top, 1.5'' bottom
- Rear Derailleur
- SRAM X01 Eagle
- Stem
- Bontrager Line Pro, 35mm, Knock Block, Blendr compatible, 0 degree
- Accessories & Extras
- Bontrager BITS Internal Frame Storage Bag
- Axles
- Front: 110 x 15mm thru-axle Rear: 148 x 12mm thru-axle
- Brakes
- SRAM G2 RSC 4-piston hydraulic disc w/SRAM CenterLine, 6-bolt, round-edge rotors
- Cassette
- SRAM Eagle XG-1275, 10-52, 12 speed
- Chainrings
- 30T alloy ring
- Fork
- Fox Factory 36, Float EVOL air spring, GRIP2 damper, tapered steerer, 44mm offset, 15mm Kabolt axle, 140mm travel
- Frame
- OCLV Mountain Carbon main frame & stays, internal storage, tapered head tube, Knock Block, Control Freak internal routing, Carbon Armor, ISCG 05, magnesium rocker link, Mino Link, ABP, 130mm travel
- Seat Post
- Bontrager Line Elite Dropper, 100mm travel, internal routing, 31.6mm; XS – S: 100mm travel / M – ML: 150mm travel / L – XL: 170mm travel
- Shifters
- SRAM X01 Eagle, 12 speed
- Tape/Grips
- Bontrager XR Trail Elite, alloy lock-on
- Color
- Matte Carbon Smoke
- Size
- X-Large
- Wheel Size
- 29-inch
- Front Tire
- Bontrager XR4 Team Issue, Tubeless Ready, Inner Strength sidewall, aramid bead, 120 TPI, 2.60 / 2.40"
What to check when buying used
Inspection
Drivetrain wear
Check chain stretch, cassette teeth, chainrings, and shifting under load before negotiating price.
Inspection
Service history
Ask for service records covering bearings, brakes, drivetrain, and any frame or fork warranty work.
Inspection
Suspension service
Confirm fork and rear shock service intervals and check pivot bearings for play.