TREK TOP FUEL 9.9 XX AXS GEN 4 MTB BIKE 2025 MATTE DARK WEB

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.

Key Features Trek Top Fuel 9.9 XX AXS Gen 4 Full Suspension MTB Bike 2025

• Carbon Fibre Frame: The Top Fuel Gen 4 delivers with an intensely lightweight build
• Frame Storage: In-frame storage with an improved BITS bag system makes it easy to stash tools, tubes and snacks
• Wireless Transmission: Ultra-clean shifting thanks to the ultra-lightweight SRAM XX AXS wireless transmission

Full Specification

• 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
• Rear Shock: RockShox Deluxe Ultimate RCT, 185 mm x 50 mm
• Fork: RockShox Pike Ultimate fork 130 mm with DebonAir spring and Charger 3.1 RC2 damper
• Shifters: SRAM AXS
• Crankset: SRAM XX Eagle, DUB, 30T, T-Type, 55mm chainline, 170 mm length
• Cassette: SRAM Eagle XS-1299, T-Type, 10-52, 12-speed
• Chain: SRAM XX Eagle, T-Type, 12-speed
• Rear Derailleur: SRAM XX SL Eagle AXS, T-Type
• Bottom Bracket: SRAM DUB MTB Wide, 73 m, BSA threaded
• Pedals: Not supplied
• Rims: Bontrager TLR
• Front Hub: Size: S - Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, 6-bolt, Boost110, 15 mm thru-axle, 27.5", Size: M, ML, L, XL - Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, 6-bolt, Boost110, 15 mm thru-axle, 29"
• Rear Hub: Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless-Ready, Rapid Drive 108, 6-bolt, Boost148, 12 mm thru axle
• Tyres: 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"
• Brakes: SRAM Level Ultimate 4-piston hydraulic disc
• Handlebars: Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 45 mm (35 mm for Small) stem length
• Stem: Bontrager RSL Integrated, see handlebars
• 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
• Weight: M - 12.85 kg / 28.33 lbs (with TLR sealant, no tubes), 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.

At All Terrain Cycles, we want you to ride with confidence every time. To ensure your bike or e-bike stays in peak condition, here are some essential safety and maintenance tips.

Bicycle Safety 

Always wear a helmet – Safeguard against head injuries by using a properly fitted, safety-certified helmet.

Perform pre-ride checks – Before each ride, verify that brakes, tyres, and gears are in good working order.

Stay visible – Utilise lights and reflective gear when cycling in low-light conditions.

Follow road rules – Ride responsibly and remain aware of your surroundings.

Aftercare for Your New Bike Initial Check-Up (First 50-100 miles)

Gear Adjustment – New cables may stretch slightly; have a qualified mechanic check and adjust them.

Brake & Wheel Check – Inspect brakes for wear and ensure wheels are aligned properly.

Lubrication – Apply chain oil and check bolt tightness to maintain smooth performance.

Tyre Pressure – Regularly monitor to prevent flats and enhance efficiency.

Pedals - Ensure pedals are still tight and correctly fitted.

Routine Maintenance (Every Few Weeks)

Chain Care – Clean and lubricate your chain to minimise wear and prolong its life.

Brake Safety – Check brake pads and responsiveness before each ride.

Tyre Inspection – Look for punctures and ensure correct air pressure.

Handlebar & Stem Alignment – Confirm they are tight and secure to prevent instability.

Frame Safety Check – Look for any signs of damage or cracks.

Pedals - Ensure pedals are still tight and correctly fitted.

Professional Check-Ups

Have your bike serviced at least once a year, or more frequently if you ride often.

Aftercare for Your New Electric Bicycle (e-Bike) Initial Check-Up (First 50-100 miles)

Battery Care – Fully charge your battery (if required) before the first ride and store it in a dry, moderate-temperature environment.

Avoid Overcharging – Unplug the charger once fully charged to extend battery life.

Pedals - Ensure pedals are still tight and correctly fitted.

Routine e-Bike Maintenance (Every Few Weeks)

Motor Inspection – Listen for unusual noises and ensure smooth operation.

Battery & Connection Checks – Inspect cables and connectors for dirt, moisture, or damage.

Pedals - Ensure pedals are still tight and correctly fitted.

Seasonal e-Bike Maintenance

Check Electrical Components – Ensure wires and connections are clean and secure.

Professional Servicing – Have your e-bike inspected at least once a year or every 500-1000 miles for optimal performance.

By following these aftercare guidelines, you’ll help ensure that your bicycle runs smoothly, lasts longer, and remains a joy to ride. Stay safe and enjoy the ride!

Read our full advice

If you have any problems or concerns: Contact All Terrain Customer Services on 01274 588488 or email sales@allterraincycles.co.uk