The 2025 Trek Top Fuel 9.9 XX AXS Gen 4 is a carbon full-suspension trail bike designed to deliver elite performance on climbs and descents. Featuring Trek’s OCLV Mountain Carbon frame, it offers 120 mm of rear travel paired with a 130 mm fork, and suspension geometry that’s adjustable via the 4-way Mino Link. With a wireless SRAM XX AXS 12-speed drivetrain, high-end RockShox Ultimate suspension, and carbon wheels, this bike combines agility, stiffness, and modern tech into one refined package.