Bikes up to 60% offWe monitor over 40,000 bikes daily to find the best prices
Today’s Deals2025 Trek
Top Fuel 9 Gen 4
A 27.5″ / 29″ aluminum frame full suspension trail bike with high-end components.
Compare the full range
Manufacturer Price
$5,249| Weight | 31.7 lbs |
|---|---|
| Frame | Aluminum |
| Suspension | Full, 120 / 130mm |
| Fork | Fox Rhythm Float 34 |
| Shock | Fox Float DPS Performance |
| Wheels | 27.5″ / 29″ Aluminum |
| Drivetrain | 1 × 12 Electronic |
| Groupset | Eagle AXS, GX Eagle Transmission |
| Brakes | SRAM Level Hydraulic Disc |
| Seatpost | Dropper |
Based on build material and quality level of the frame, fork, wheelset, groupset, suspension system, and more.
Compare the full Top Fuel model range
View Comparison5'1" – 5'6"
5'4" – 5'10"
5'8" – 5'11"
5'9" – 6'3"
6'1" – 6'5"
None yet.
Do you have this bike? Help other riders make a decision about which size will work for them by sharing your own size and fit notes.
Summary
The Trek Top Fuel is a versatile trail bike that excels in efficiency and adjustability, offering a lightweight design and stellar climbing performance. However, it faces criticism for its demanding handling and less premium component choices. Its suspension is well-balanced but firmly tuned, making it a mixed bag for riders seeking both comfort and performance.
Very efficient climber
Extensive adjustability options
Lightweight
Good value for money
Precise, reliable shifting even under load
Very little stability at speed
Demanding handling
Underwhelming component choices
Less premium-looking design
Limited freedom of movement on technical trails due to short dropper post
The Trek Top Fuel is the outsider in our 2025 trail bike comparison test, and looks more like a beefed-up XC bike than a true trail bruiser.
Enduro Mountainbike MagazineIt’s a keen climber that balances rider weight well while keeping handling lively and sharp.
off.road.ccThe new Top Fuel responds to your fierce input like an XC bike; the torsionally stiff and responsive frame makes the most of your pedal strokes, and you find yourself moving faster than expected.
Outdoor Gear LabFeedback?
View all reviews
Aug 2025 · Cole Gregg
Trek have done an excellent job with the Top Fuel 9, producing a bike that rips the climbs and still has legs for a rowdy descent.
Jun 2025 · Dario DiGiulio
Honestly, I think Trek could do a slight reshuffle of their lineup. Call this bike the Fuel, and use the 130 / 140mm configuration as the stock setup. That would open the door for a lightweight 120/120 flexstay thing that's truly deserving of the Top Fuel moniker.
Apr 2025 · Simon Kohler
In our 2025 big trail bike comparison test, the Trek Top Fuel 9.8 GX AXS takes on the hottest bikes of the season. How does it fare against the competition?
Very efficient climber
Extensive adjustability options
Very little stability at speed
Demanding handling
Underwhelming component choices
Less premium-looking design
Feb 2025 · Joshua Hutchens
The new Top Fuel is the 4th generation of Trek's lightweight, short-travel trail bike, gaining more versatility and some cool functionality. This...
Adjustable geometry and leverage
Frame storage with BITS
ABP suspension
Bar/stem combo limits adjustability
Heavier wheels
Tires provide a speed limit
Jan 2025
Although raced by Evie Richards on the elite-level cross-country circuit, Trek’s latest Top Fuel 8 Gen 4 is a bike that’ll cater to a raft of tastes thanks to its impressive adaptability. Despite the meagre suspension travel, it dishes out stellar trail manners up and downhill and is primed for UK trails.
Nov 2024 · Spencer Astra
We’re getting deeper into autumn in the Pacific Northwest. This shift leads to slick trails and cooler temperatures. The new Trek Top Fuel seems to be the perfect companion to scoot around the mountain and dodge puddles. This bike immediately caught my attention, delivering an unexpectedly fun and efficient experience in a sleek, trail-friendly package. With a lightweight, carbon frame and components tuned for speed and control, the Top Fuel has quickly become a bike I look forward to riding.
Oct 2024
3 months aboard the 9.8 GX AXS version of Trek's XC-plus, trail-lite, most of the bell curve-targeted Top Fuel
Excellent pedaling and climbing efficiency
Cohesive design and balanced riding position
Well-matched suspension (Rockshox Pike/Deluxe)
Clean fit and finish, no creaks or rattles
Quiet and composed ride
Versatile and adaptable platform
Uncomfortable Trek Verse Comp saddle
Bontrager Line dropper post has fore-aft play
SRAM Level Bronze brakes lack bite on long descents
RSL integrated bar/stem too stiff, no adjustability
Heavy wheelset (close to 2000g) on $7000 carbon bike
Bike weight nearly 30 lbs, especially in wheels
Oct 2024 · Jeff Barber
The Trek Top Fuel is a short-travel mountain bike that tries to do a lot of things, though I found it's really an XC bike at heart.
Efficient pedaling, as long as the climbing is shock set to firm
A joy on descents
Bontrager components are surprisingly solid
Not as comfortable or playful as other downcountry bikes
Fit might be tricky for some riders
Can’t get away with leaving the shock open for the whole ride
| Frame | Alpha Platinum Aluminum, internal storage, tapered head tube, internal guided routing, downtube guard, alloy rocker link, 4-way Mino Link, ABP, Boost148, 120mm travel BB Standard: BSA, 73mm, Threaded Hanger Standard: UDH Tire Clearance: 2.5" Color: Juniper |
|---|---|
| Fork | Fox Rhythm 34, Float EVOL air spring, GRIP damper, tapered steerer, 44mm offset, Boost110, 15mm Kabolt axle, 130mm travel Travel: 130mm Spring Type: Air |
| Shock | Fox Performance Float DPS, 2-position damper, 185mm x 50mm Travel: 120mm |
| Bottom Bracket | SRAM DUB MTB Wide, 73mm, BSA threaded |
| Stem | Bontrager Elite, 35mm, 0 degree, 45mm length |
| Handlebar | Bontrager Line, alloy, 35mm, 27.5mm rise, 780mm width |
| Saddle | Verse Short Comp, steel rails, 145mm width |
| Seatpost | Bontrager Line Dropper, 100mm travel, MaxFlow, internal routing, 34.9mm, 310mm length - S : Bontrager Line Dropper, 100mm travel, MaxFlow, internal routing, 34.9mm, 310mm length; M, ML, L, XL: Bontrager Line Dropper, 170mm travel, MaxFlow, internal routing, 34.9mm, 450mm length Type: Dropper |
| Grips | Bontrager XR Trail Comp, nylon lock-on |
| Rear Derailleur | SRAM GX Eagle AXS, T-Type |
|---|---|
| Crank | SRAM GX Eagle, T-Type, DUB, 30T, 55mm chainline, 170mm length |
| Shifters | SRAM AXS POD |
| Cassette | SRAM Eagle XS-1275, T-Type, 10-52, 12 speed |
| Chain | SRAM GX Eagle, T-Type, 12 speed |
| Brakes | SRAM Level Bronze 4-piston hydraulic disc Type: SRAM Level Hydraulic Disc |
| Rims | Front: Bontrager Line Comp 30 TLR 6-bolt Disc, Boost, Black spokes and nipples - S : Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle, 27.5''; M, ML, L, XL: Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle, 29'', Rear: Bontrager Line Comp 30 Boost TLR 27.5'' Rear Wheel, 28H, SRAM XD, 6-bolt Disc, 12mm Thru Axle, Black/Black - S : Bontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Boost148, 12mm thru axle, 27.5''; M, ML, L, XL: Bontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Boost148, 12mm thru axle, 29'' |
|---|---|
| Tires | Bontrager Gunnison Pro XR, Tubeless Ready, wire bead, 60 tpi, 27.5x2.40'', tan sidewall - S : Bontrager Gunnison Pro XR, Tubeless Ready, wire bead, 60 tpi, 27.5x2.40''; M, ML, L, XL: Bontrager Gunnison Pro XR, Tubeless Ready, dual compound, aramid bead, 60 tpi, 29x2.40'' |
| Disc Rotors | SRAM CenterLine, 6-bolt, round edge, 180mm |
First added July 11
Last updated April 4
Not listed for 84 days