Trek Top Fuel 9.9 X0 AXS Gen 4 - Carbon Mountain Bike - 2026 - 27.5" - Lunar Silver

Outstanding performance on the trail

The Top Fuel 9.9 X0 AXS Gen 4 is an ultra-lightweight and extremely capable carbon trail bike built for efficient climbs and miles of single-track adventures. This top-of-the-line trail bike delivers ultimate performance: a RockShox Ultimate suspension package with 130 mm of front and 120 mm of rear travel, and a wireless SRAM X0 AXS drivetrain for exceptionally smooth and precise shifting. Rounding out this premium spec are carbon wheels that contribute to the bicycle’s lightweight design.

Highlights of the Trek Top Fuel 9.9 X0 AXS Gen 4 - Carbon Mountain Bike

• Lightweight and stiff full-carbon frame with integrated storage compartment.
• Additional carbon components keep the weight down.
• RockShox Pike Ultimate suspension fork with 130 mm of front travel.
• RockShox Deluxe Ultimate RCT rear shock with 120 mm of rear travel.
• Lightning-fast shifting is enabled by the wireless, electronic 12-speed SRAM X0 Eagle AXS drivetrain.
• Wide Line Pro 30 carbon wheels improve tire contact, allowing you to ride with lower tire pressure for more traction.
• The Rapid Drive hub with 108 teeth ensures instant power transfer.

Top Fuel 9.9 technologies

• Active Braking Pivot - allows Trek engineers to fine-tune how the suspension responds independently to acceleration and braking forces. This gives you more confidence in critical situations.
• Threaded bottom bracket - is more durable than press-fit bearings, withstands the toughest conditions, and simplifies maintenance.
• Internal storage options with BITS bags - Thanks to the integrated frame bags, you can leave your backpack at home without having to go without the essentials.
• Per Mino Link adjustable geometry – Adjust the head angle (by 0.5°) and bottom bracket height (by up to 10 mm) by simply turning a threaded nut. Turn the nut and choose between a flat and an even flatter geometry without compromising the performance of the suspension. Another exclusive Trek technology.