2025 Trek Top Fuel 9.9 XX AXS Gen 4
The Top Fuel 9.9 XX 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 lightest wireless XX 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.
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OVERVIEW
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SPECS
It's right for you if...
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-lightweight benefits of SRAM's XX AXS wireless transmission and an upgraded RockShox Ultimate suspension package is a must.
The tech you get
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. An ultra-light wireless SRAM XX AXS transmission, SRAM Level Ultimate 4-piston hydraulic brakes, RockShox Reverb AXS dropper post and tubeless-ready Bontrager Line Pro 30 carbon wheels.
The final word
When you're after the best all-mountain carbon ride, reach for the Top Fuel 9.9 XX AXS Gen 4. With an ultra-light frame, carbon wheels and SRAM XX 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.
Why you'll love it
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.
*Please note – spec applies to all sizes unless listed separately
Frameset
Frame 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
Shock RockShox Deluxe Ultimate RCT, 185 mm x 50 mm
Max compatible fork travel 140 mm
Wheels
Wheel front Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless-Ready, 6-bolt, Boost110, 15 mm thru-axle
Wheel rear Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, Rapid Drive 108, 6-bolt, SRAM XD driver, Boost148, 12 mm thru-axle
Skewer rear Bontrager Switch thru-axle, removable lever
*Tyre
Size: S
Bontrager Gunnison RSL XT, Tubeless-Ready, triple compound, aramid bead, 120 tpi, 27.5x2.40"
Size: M, ML, L, XL
Bontrager Montrose RSL XT, Tubeless-Ready, triple compound, aramid bead, 120 tpi, 29x2.40"
Size: M, ML, L, XL
Bontrager Gunnison RSL XT, Tubeless-Ready, triple compound, aramid bead, 120 tpi, 29x2.40"
Tyre part Bontrager TLR sealant, 180 ml/6 oz
Max tyre size Frame: 29x2.50", Fork: See manufacturer
E-system
Battery SRAM eTap battery pack (with charger)
Drivetrain
Rear derailleur SRAM XX SL Eagle AXS, T-Type
Crank SRAM XX Eagle, DUB, 30T, T-Type, 55 mm chainline, 170 mm length
Bottom bracket SRAM DUB MTB Wide, 73 m, BSA threaded
Cassette SRAM Eagle XS-1299, T-Type, 10-52, 12-speed
Chain SRAM XX Eagle, T-Type, 12-speed
Max. chainring size 1x: 34T, min 30T
Components
Saddle Verse Short Pro, carbon rails, 145 mm width
*Seatpost Size: S
RockShox Reverb AXS, 100 mm travel, wireless, 34.9 mm, 340 mm length
Size: M, ML, L, XL
RockShox Reverb AXS, 170 mm travel, wireless, 34.9 mm, 480 mm length
*Handlebar/stem (integrated) Size: S
Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 35 mm stem length
Size: M, ML, L, XL
Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 45mm stem length
*Brake Size: S , M, ML, L, XL
SRAM Level Ultimate 4-piston hydraulic disc
Size: S , M, ML, L, XL
SRAM Level Ultimate Stealth 4-piston hydraulic disc
Brake rotor SRAM HS2, 6-bolt, 180mm
Rotor size Max brake rotor sizes – Frame: 200 mm, min 180 mm, Fork: see fork manufacturer
Weight
Weight M - 12.85 kg / 28.33 lbs (with TLR sealant, no tubes)
Weight limit This bike has a maximum total weight limit (combined weight of bicycle, rider and cargo) of 136 kg (300 lb).
We reserve the right to make changes to the product information contained on this site at any time without notice, including with respect to equipment, specifications, models, colours, materials and pricing. Due to supply chain issues, compatible parts may be substituted at any time without notice.
Bike and frame weights are based on pre-production painted frames at time of publication. Weights may vary in final production.
Shipping
We aim to have each order fulfilled and shipped within 3-5 working days after your order being paid.
Link to your shipping policy.
Delivery
Shop online at biket and choose between 2 convenient delivery options.
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Door-to-door courier countrywide.
Refunds
Please note we do not offer straight refunds, these are issued as store credits only.
WHO ARE WE
Biket is one of South Africas Top Online Cycling Stores, based in Hillcrest, KZN.
We offer a range of the highest quality cycling products from Trek bikes, Giant bikes, Scott bikes, Bontrager & Oakley apparel, and a full service centre. Our aim is to offer the highest quality cycling products paired with the best advice.
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