The Ultimate Performance Trail Bike
The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle is a performance-first trail bike built for riders who appreciate the finest things in life . Combining a featherweight OCLV Mountain Carbon frame with top-tier components, this bike dominates the mountain — ripping rock gardens, blasting berms, and rocketing back to the summit .
OCLV Mountain Carbon Frame with Internal Storage
The frame is constructed from Trek’s premium OCLV Mountain Carbon, offering an exceptional strength-to-weight ratio . The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle features internal frame storage, allowing you to ditch the pack and carry ride essentials inside the downtube . A magnesium rocker link, downtube guard, shuttle guard, and Active Braking Pivot (ABP) complete the refined chassis .
Fully Wireless SRAM XX1 Eagle AXS Drivetrain
The drivetrain is the crown jewel of this build. SRAM’s top-tier XX1 Eagle AXS wireless electronic system delivers precise, lightning-fast gear changes — even when shifting under load . The 12-speed setup features a 10-52T cassette and a 30T alloy chainring, providing massive climbing range and flawless performance .
Fox Factory 36 Fork and Float X Rear Shock
Up front, a Fox Factory 36 fork with 150mm travel features a Float EVOL air spring, GRIP2 damper, and iconic Kashima coating for silky-smooth suspension feel . Out back, a Fox Factory Float X shock provides 140mm of travel with a 2-position damper .
SRAM Code RSC 4-Piston Hydraulic Disc Brakes
Stopping power comes from SRAM Code RSC 4-piston hydraulic disc brakes with SwingLink technology . These brakes provide exceptional modulation and fade-free performance, equipped with 180mm rotors (200mm on larger sizes) .
Bontrager Line Pro Carbon Wheels
The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle rolls on Bontrager Line Pro 30 carbon wheels . The Rapid Drive 108 rear hub provides nearly instant acceleration with 108 points of engagement — eliminating clunky lag when you step on the pedals .
RockShox Reverb AXS Wireless Dropper Post
A RockShox Reverb AXS wireless dropper post lets you lower your saddle at the push of a button . Travel is size-specific (100mm, 150mm, or 170mm) with a 34.9mm diameter for increased stiffness .
Bontrager SE5 Team Issue Tubeless Tires
The bike comes equipped with Bontrager SE5 Team Issue tires, featuring Core Strength sidewalls for puncture resistance . They’re Tubeless Ready with included TLR sealant, valves, and rim strips .
Adjustable Geometry with Mino Link
Fine-tune your ride with Mino Link adjustable geometry . Flip the link to adjust the head tube angle by half a degree and bottom bracket height by up to 10mm — all without negatively affecting suspension performance .
Adjustable Leverage Rate (Progressive/Linear)
Flip a chip on the rocker link to adjust the suspension leverage rate . Choose “Less Progressive” for a plusher feel ideal for rugged trails, or “More Progressive” when hitting big features or running a coil shock.
Mullet-Ready Frame Design
Mullet setup (29″ front, 27.5″ rear) is ready to go — just throw Mino Link into high, toss on a 160mm fork, and enjoy the nimble rear end with the rollover of a 29er.
Internal Routing and Threaded Bottom Bracket
Guided internal routing keeps the cockpit clean . A threaded BSA 73mm bottom bracket is more robust than press-fit designs, holding up in nasty conditions and simplifying service.
ISCG 05 Chain Guide Mounts
ISCG 05 tabs allow easy chain-guide installation for riders tackling the roughest terrain where chain retention is critical.
Active Braking Pivot (ABP) Technology
ABP allows engineers to tune how suspension reacts to acceleration and braking forces independently . The suspension remains active even under hard braking, maintaining traction through corners.
Size-Specific Chainstays and Wheel Sizes
Size-specific chainstays balance handling for all riders . Wheel size is tailored to frame size: XS gets 27.5″, S can choose 27.5″ or 29″, and sizes M and up get 29″.
Complete Tubeless System
Tubeless Ready rims and tires come with everything needed to ditch the tubes. Better traction, fewer flats, less weight — you’re ready to roll straight out of the box.
Bontrager Integrated Carbon Bar/Stem
The Bontrager RSL integrated OCLV Carbon bar/stem reduces weight, increases stiffness, and cleans up the cockpit . A 27.5mm rise, 820mm width, and 35-45mm length deliver confident handling.
Bontrager Arvada Saddle
The Bontrager Arvada saddle features austenite rails and a 138mm width, balancing comfort and performance for long days on the trail.
Weight
Weighing just 14.11 kg (31.11 lbs) for a size medium, this is exceptionally light for a full-power trail bike.
Sizing and Fit
- XS: 4’9″ – 5’1″ (145-155 cm) — 27.5″ wheels
- S: 5’1″ – 5’5″ (155-165 cm) — 27.5″ or 29″ wheels
- M: 5’5″ – 5’9″ (165-176 cm) — 29″ wheels
- ML: 5’8″ – 5’11” (173-180 cm) — 29″ wheels
- L: 5’10” – 6’2″ (177-188 cm) — 29″ wheels
- XL: 6’2″ – 6’5″ (188-196 cm) — 29″ wheels
Pros:
- OCLV Mountain Carbon frame
- SRAM XX1 Eagle AXS wireless 12-speed drivetrain
- Fox Factory 36 fork (150mm) + Float X shock (140mm) with Kashima
- SRAM Code RSC 4-piston hydraulic disc brakes
- Bontrager Line Pro carbon wheels (Rapid Drive 108 hub)
- RockShox Reverb AXS wireless dropper post
- Adjustable geometry (Mino Link) + adjustable leverage rate
- Mullet-ready frame design
- Internal frame storage
- Weight: 14.11 kg (31.11 lbs)
- Threaded BSA bottom bracket
Cons:
- Very expensive (flagship pricing)
- Pedals not included
- May be overkill for casual trail riders
- Requires AXS battery management
Frame and Suspension Specifications
- Frame: OCLV Mountain Carbon, internal storage, angle-adjust headset, Mino Link, adjustable leverage rate, guided internal routing, magnesium rocker link, 34.9mm seat tube, ISCG 05, 55mm chainline, BSA 73, downtube guard, shuttle guard, ABP, UDH, Boost148, 140mm travel
- Fork: Fox Factory 36, Float EVOL air spring, GRIP2 damper, tapered steerer, 44mm offset, Kashima coating, Boost110, 15mm Kabolt axle, 150mm travel
- Rear Shock: Fox Factory Float X, 2-position damper, 185mm x 55mm
Drivetrain Specifications
- Shifters: SRAM Eagle AXS, wireless, 12-speed
- Rear Derailleur: SRAM XX1 Eagle AXS
- Crankset: SRAM XX1 Eagle, DUB, 30T alloy ring, 55mm chainline, 170mm length
- Bottom Bracket: SRAM DUB MTB Wide, 73mm, BSA threaded
- Cassette: SRAM Eagle XG-1299, 10-52T, 12-speed
- Chain: SRAM XX1 Eagle, 12-speed
Brake Specifications
- Brakes: SRAM Code RSC 4-piston hydraulic disc
- Rotors: SRAM HS2, 6-bolt, 180mm (XS/S/M/ML) / 200mm (L/XL)
Wheel and Tire Specifications
- Wheels: Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready
- Front Hub: Boost110, 15mm thru-axle
- Rear Hub: Rapid Drive 108, 108 points of engagement, SRAM XD driver, Boost148, 12mm thru-axle
- Tires: Bontrager SE5 Team Issue, Tubeless Ready, Core Strength sidewalls, aramid bead, 120 tpi, 29″ x 2.50″ (27.5″ x 2.50″ on XS/S)
Component Specifications
- Handlebar/Stem: Bontrager RSL integrated, OCLV Carbon, 27.5mm rise, 820mm width, 0° stem rise, 35-45mm length
- Grips: Bontrager XR Trail Elite, nylon lock-on
- Saddle: Bontrager Arvada, austenite rails, 138mm width
- Seatpost: RockShox Reverb AXS, wireless, 34.9mm (100/150/170mm travel size-specific)
- Headset: Integrated cartridge bearing, 1-1/8″ top, 1.5″ bottom, angle-adjust cup compatible
Weight and Limits
- Weight: 14.11 kg (31.11 lbs) for size M
- Weight Limit: 136 kg (300 lbs) total (bike, rider, cargo combined)
Colors
- Deep Smoke, Mulsanne Blue, Satin Baja Yellow
Who Is This Bike For?
The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle is perfect for:
- Riders who demand the finest components available
- Trail and enduro enthusiasts tackling technical descents
- Weight-conscious riders wanting a sub-32 lb full-power trail bike
- Technology lovers who appreciate wireless shifting and droppers
- Anyone wanting a bike that can be fine-tuned to their exact preferences
Why Choose the Fuel EX 9.9 XX1 AXS Gen 6?
The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle represents the absolute pinnacle of Trek’s trail bike lineup . You want a bike built to tackle the whole mountain with the finest technology the industry has to offer — from its light and stiff carbon frame and wheels that track through the hairiest lines, to the Fox Factory fork and fully wireless SRAM XX1 group set .
The wireless AXS ecosystem is the standout feature, keeping the cockpit clean and eliminating cable maintenance . The adjustable geometry and leverage rate let you fine-tune the bike to your riding style and terrain . The carbon wheels, frame, and integrated bar/stem keep weight exceptionally low .
For riders who demand the absolute best and have the budget to match, the TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle is the ultimate trail weapon.
For more options, browse our Collection of Trail Mountain Bikes or read our Mountain Bike Buying Guide to find your perfect match.n and braking forces independently . You get more confident control when you need it most — the suspension remains active even under hard braking, maintaining traction through corners .
Size-Specific Chainstays and Wheel Sizes
Size-specific chainstays balance handling for all riders — keeping the ride nimble for smaller riders and improving front wheel traction on climbs for taller riders . Wheel size is tailored to frame size: XS frames get 27.5″ wheels, S frames can choose 27.5″ or 29″, and sizes M and up get 29″ for maximum rollover .
Complete Tubeless System
Tubeless Ready rims and tires come with everything needed to ditch the tubes. Better traction, fewer flats, less weight — you’re ready to roll straight out of the box .
Bontrager Integrated Carbon Bar/Stem
The Bontrager RSL integrated OCLV Carbon bar/stem reduces weight, increases stiffness, and cleans up the cockpit . A 27.5mm rise, 820mm width, and 35-45mm length deliver confident handling and control.
Bontrager Arvada Saddle
The Bontrager Arvada saddle features austenite rails and a 138mm width, balancing comfort and performance for long days on the trail .
Weight
Weighing just 14.11 kg (31.11 lbs) for a size medium, this is exceptionally light for a full-power trail bike .
Sizing and Fit
- XS: 4’9″ – 5’1″ (145-155 cm) — 27.5″ wheels
- S: 5’1″ – 5’5″ (155-165 cm) — 27.5″ or 29″ wheels
- M: 5’5″ – 5’9″ (165-176 cm) — 29″ wheels
- ML: 5’8″ – 5’11” (173-180 cm) — 29″ wheels
- L: 5’10” – 6’2″ (177-188 cm) — 29″ wheels
- XL: 6’2″ – 6’5″ (188-196 cm) — 29″ wheels
Who Is This Bike For?
The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle is perfect for:
- Riders who demand the finest components available
- Trail and enduro enthusiasts tackling technical descents
- Weight-conscious riders wanting a sub-32 lb full-power trail bike
- Technology lovers who appreciate wireless shifting and droppers
- Anyone wanting a bike that can be fine-tuned to their exact preferences
Pros:
- CRUSHINGLY EXPENSIVE OCLV Mountain Carbon frame
- SRAM XX1 Eagle AXS wireless 12-speed drivetrain
- Fox Factory 36 fork (150mm) + Float X shock (140mm) with Kashima
- SRAM Code RSC 4-piston hydraulic disc brakes
- Bontrager Line Pro carbon wheels (Rapid Drive 108 hub)
- RockShox Reverb AXS wireless dropper post
- Adjustable geometry (Mino Link) + adjustable leverage rate
- Mullet-ready frame design
- Internal frame storage
- Weight: 14.11 kg (31.11 lbs)
- Threaded BSA bottom bracket
- Carbon Care Wheel Loyalty Programme
Cons:
- Very expensive (flagship pricing)
- Pedals not included
- May be overkill for casual trail riders
- Requires AXS battery management
TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle: Technical Specifications
Frame and Suspension
- Frame: OCLV Mountain Carbon, internal storage, angle-adjust headset, Mino Link, adjustable leverage rate, guided internal routing, magnesium rocker link, 34.9mm seat tube, ISCG 05, 55mm chainline, BSA 73, downtube guard, shuttle guard, ABP, UDH, Boost148, 140mm travel
- Fork: Fox Factory 36, Float EVOL air spring, GRIP2 damper, tapered steerer, 44mm offset, Kashima coating, Boost110, 15mm Kabolt axle, 150mm travel
- Rear Shock: Fox Factory Float X, 2-position damper, 185mm x 55mm
Drivetrain
- Shifters: SRAM Eagle AXS, wireless, 12-speed
- Rear Derailleur: SRAM XX1 Eagle AXS
- Crankset: SRAM XX1 Eagle, DUB, 30T alloy ring, 55mm chainline, 170mm length
- Bottom Bracket: SRAM DUB MTB Wide, 73mm, BSA threaded
- Cassette: SRAM Eagle XG-1299, 10-52T, 12-speed
- Chain: SRAM XX1 Eagle, 12-speed
Brakes
- Brakes: SRAM Code RSC 4-piston hydraulic disc
- Rotors: SRAM HS2, 6-bolt, 180mm (XS/S/M/ML) / 200mm (L/XL)
Wheels and Tires
- Wheels: Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready
- Front Hub: Boost110, 15mm thru-axle
- Rear Hub: Rapid Drive 108, 108 points of engagement, SRAM XD driver, Boost148, 12mm thru-axle
- Tires: Bontrager SE5 Team Issue, Tubeless Ready, Core Strength sidewalls, aramid bead, 120 tpi, 29″ x 2.50″ (27.5″ x 2.50″ on XS/S)
Components
- Handlebar/Stem: Bontrager RSL integrated, OCLV Carbon, 27.5mm rise, 820mm width, 0° stem rise, 35-45mm length
- Grips: Bontrager XR Trail Elite, nylon lock-on
- Saddle: Bontrager Arvada, austenite rails, 138mm width
- Seatpost: RockShox Reverb AXS, wireless, 34.9mm (100/150/170mm travel size-specific)
- Headset: Integrated cartridge bearing, 1-1/8″ top, 1.5″ bottom, angle-adjust cup compatible
Weight and Limits
- Weight: 14.11 kg (31.11 lbs) for size M
- Weight Limit: 136 kg (300 lbs) total (bike, rider, cargo combined)
Colors
Why Choose the Fuel EX 9.9 XX1 AXS Gen 6?
The TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle represents the absolute pinnacle of Trek’s trail bike lineup . You want a bike built to tackle the whole mountain with the finest technology the industry has to offer — from its light and stiff carbon frame and wheels that track through the hairiest lines, to the Fox Factory fork and fully wireless SRAM XX1 group set .
The wireless AXS ecosystem is the standout feature, keeping the cockpit clean and eliminating cable maintenance . The adjustable geometry and leverage rate let you fine-tune the bike to your riding style and terrain . The carbon wheels, frame, and integrated bar/stem keep weight exceptionally low for a 150/140mm travel bike .
Customer reviews praise the Fuel EX 9.9 for its ability to “rip up rock gardens, blast berms, and rocket back to the top” . The combination of the ultra-progressive geometry and top-tier suspension makes light work of steep, punchy climbs and turns around to rally the descents .
For riders who demand the absolute best and have the budget to match, the TREK Fuel EX 9.9 XX1 AXS Gen 6 Bicycle is the ultimate trail weapon.
For more options, browse our Collection of Trail Mountain Bikes or read our Mountain Bike Buying Guide to find your perfect match
