2025 Top Fuel 9.9 X0 AXS Gen 4


The Top Fuel 9.9 X0 AXS Gen 4 is an ultra-light and capable carbon trail bike that's built for soaring up climbs and rallying over miles of singletrack. This top-level build delivers the performance you want, with a RockShox Ultimate suspension package (120 mm/130 mm) and SRAM's wireless X0 AXS transmission that shifts smooth and easy, especially under load. It's topped off with carbon wheels to keep your ride light from top to bottom.

You want the best carbon trail bike with all-mountain capability, climbing efficiency and components to match. You don't mind spending a little extra to get the ultra-clean shifting of SRAM's X0 AXS wireless transmission and an upgraded RockShox Ultimate suspension package is a must.

An OCLV Mountain Carbon frame with a 4-way Mino Link lower shock mount for tweaking geometry and suspension leverage rate. A 130 mm RockShox Pike Ultimate fork with DebonAir spring and Charger 3.1 RC2 damper, plus 120 mm of rear travel from a RockShox Deluxe Ultimate RCT shock. A wireless SRAM X0 AXS transmission, SRAM Level Silver Stealth 4-piston hydraulic brakes, RockShox Reverb AXS dropper post and tubeless-ready Bontrager Line Pro 30 carbon wheels.

When you're after the best all-mountain carbon ride, reach for Top Fuel X0 AXS 9.9 Gen 4. With an ultra-light frame, carbon wheels and SRAM X0 wireless transmission, it delivers everything you want on dirt. Plus, it's built with a 4-way Mino Link lower suspension mount for taking control of your geometry and suspension feel.
- The Top Fuel Gen 4 delivers with an intensely lightweight build, improved in-frame storage and more adjustability for all kinds of rides and riders
- With 120 mm rear and 130 mm front RockShox Ultimate suspension, it delivers a well-balanced ride that stays efficient on the ups and playful on descents
- The 4-way Mino Link makes it easy to adjust your geometry or leverage rate for how and where you want to ride
- In-frame storage with an improved BITS bag system makes it easy to stash tools, tubes and snacks
- It's more upgrade-ready than ever, with room for bigger 140 mm forks and longer-stroke shocks for up to 130 mm of rear travel, plus room for extra-long dropper posts

Make the Top Fuel yours
Opt for light parts and a 120 mm fork for a featherweight Top Fuel, or a 140 mm fork and longer-stroke 130 mm rear shock for extra versatility. Room for a longer dropper and MX wheels lets you customise the Top Fuel into an ultimate playful trail whip.

4-way Mino Link
Easily adjust the suspension and geometry four different ways for where and how you ride. At the flip of a coin, you can ride with more or less progressive suspension and tweak your geometry for a slacker head tube and lower BB, or steeper head tube and higher BB.

New internal storage with new BITS bags
New internal frame storage bags make it easy to ditch the pack and still carry your ride essentials.

BITS: Your trail-side saviour
Cleverly integrated into the steerer tube, the included BITS multi-tool has everything you need for trail-side adjustments and repairs.

Active Braking Pivot
Active Braking Pivot allows our engineers to tune how the suspension reacts to acceleration and braking forces independently. That means you get more confident control when you need it most.

Frame Size ML, UNI, Carbon, OCLV Mountain Carbon, internal storage, tapered head tube, internal guided routing, downtube guard, OCLV Next rocker link, Mino 4 link, ABP, Boost148, 120 mm travel
Wheel Size Front 29
Wheel Size Rear 29
Fork Unknown
Gears DERAILLEUR, Sram, 1 Gears
Wheels BONTRAGER, Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, 6-bolt, Boost110, 15 mm thru-axle, 29"" Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless-Ready, Rapid Drive 108, 6-bolt, Boost148, 12 mm thru axle
Shifters SRAM, SRAM AXS POD // SRAM AXS POD, paired with dropper,
Kickstand UNKNOWN, Unknown
Front Brake SH, SRAM Level Silver 4-piston hydraulic disc // SRAM Level Silver Stealth 4-piston hydraulic disc SRAM HS2, 6-bolt, 180mm Max brake rotor size, Disc brake with hydraulic actuation
Rear Brake SH, SRAM Level Silver 4-piston hydraulic disc // SRAM Level Silver Stealth 4-piston hydraulic disc SRAM HS2, 6-bolt, 180mm Max brake rotor size, Disc brake with hydraulic actuation
Rear Derailleur ,
Crankset SRAM, SRAM X0 Eagle, DUB, 30T steel, T-Type, 55mm chainline, 170 mm length SRAM DUB MTB Wide, 73 m, BSA threaded
Chain SRAM, SRAM X0 Eagle, T-Type, 12-speed
Handlebar BONTRAGER, Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 45mm stem length
Saddle UNBRANDED, Verse Short Pro, carbon rails, 145 mm width
Front Light UNKNOWN
Rear Light UNKNOWN
Sizes L, M, ML, S, XL
Brand Trek
Model Year 2025
Barcodes 601842998779, 601842998786, 601842998793, 601842998809, 601842998816, 601842998823, 601842998830, 601842998847, 601842998854, 601842998861, 601842998922, 601842998939, 601842998946, 601842998953, 601842998960
SKUs / Part Numbers 5319388, 5319389, 5319390, 5319391, 5319392, 5319393, 5319394, 5319395, 5319396, 5319397, 5320418, 5320419, 5320420, 5320421, 5320422

Please note: Manufacturers can sometimes change the specification of the products from time to time.

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