Trek Top Fuel 9.8 Gen 4 GX AXS

Name: Trek Top Fuel 9.8 Gen 4 GX AXS
Brand: Trek

2025 MountainTrail Manufacturer page

Trek Top Fuel 9.8 Gen 4 GX AXS, color Matte Dark Web

Last known price: $7,699

Prices shown first for United States
Travel: 130 / 120 mm Fork / rear shock
Wheels: 27.5″, 29″
Drivetrain: 1 × 12 30t / 10–52t
Gear range: 520%
Weight: 13.2 kg 29.1 lb · Reference configuration not specified
Frame: Carbon
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM 155–166
SM 155–166
MD 164–177
MD 164–177
MD/LG 173–180
MD/LG 173–180
LG 177–189
LG 177–189
XL 187–195
XL 187–195

Components

16 of 18 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

OCLV Mountain Carbon, internal storage, tapered head tube, internal guided routing, downtube guard, alloy rocker link, 4-way Mino Link, ABP, Boost148, 120mm travel Not identified

Suspension

2 parts

Drivetrain

6 parts

Brakes

2 parts

Wheels and tires

3 parts

Rims
- Bontrager
Spokes

14 g stainless steel, black Not identified
Tires
- Bontrager

Cockpit and contact points

4 parts

Sizes and geometry

10 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size MD/LG

Table

Reach 467mm

Stack 604mm

Wheelbase 1210mm

Head angle 65.9°

Seat angle 76.6°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 29″ wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 10 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	422	417	452	447	467	462	482	477	512	507
Stackmm	566	570	599	603	604	607	608	612	626	630
Top tube lengthmm	558	559	587	588	611	612	630	631	672	673
Seat tube lengthmm	360	360	410	410	420	420	435	435	470	470
Head tube lengthmm	105	105	105	105	110	110	115	115	135	135
Head tube angle	65.9°	65.5°	65.9°	65.5°	65.9°	65.5°	65.9°	65.5°	65.9°	65.5°
Seat tube angle	76.5°	76°	77.3°	76.9°	76.6°	76.2°	76.3°	75.9°	75.6°	75.2°
Chainstay lengthmm	434	435	434	435	439	440	439	440	444	445
Wheelbasemm	1150	1151	1188	1188	1210	1210	1227	1227	1270	1271
Front centermm	717	717	755	755	772	772	789	789	827	827
Bottom bracket dropmm	10	16	26	32	26	32	26	32	26	32
Bottom bracket heightmm	345	339	348	342	348	342	348	342	348	342
Standover heightmm	705	700	755	750	757	752	758	753	763	758
Fork rakemm	41	43	42	43	42	43	42	43	42	43
Trailmm	111	115	121	125	121	125	121	125	121	125
Stack/reach ratio	1.34	1.37	1.33	1.35	1.29	1.31	1.26	1.28	1.22	1.24

Not published by the manufacturer: Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Carbon
Bicycle weight: 13.2 kg

29.1 lb
Weight limit: 136 kg

299.8 lb

Suspension

Suspension configuration: Full suspension
Front travel: 130 mm
Rear travel: 120 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 30
Largest chainring: 30
Rear sprockets: 12
Smallest sprocket: 10
Largest sprocket: 52
Lowest gear: 16.7 in
Highest gear: 87.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Derailleur hanger: UDH
Seatpost: Dropper seatpost
Shifting: Electronic

Additional specifications

Bottom bracket standard: BSA
Fork spring: Air
Tire clearance: Maximum tire width: 2.5″
Tire width: 2.4″
Wheel material: Aluminum
Wheel size: 27.5″, 29″

Technical analysis

4 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Front travel

130 mm

This value is within the central range for this class.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,808 bicycles with this information
Coverage: 97.5% of the class

Lowest gear

16.7 gear inches

This value is below the central range for this class.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,382 bicycles with this information
Coverage: 74.5% of the class

Highest gear

87.0 gear inches

This value is within the central range for this class.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,382 bicycles with this information
Coverage: 74.5% of the class

Shifting

Electronic

387 of 1,847 bicycles with this information use electronic shifting.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,847 bicycles with this information
Coverage: 99.6% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.4 km/h
Highest gear: 33.3 km/h

Total gear range 520%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 16.7–87.0 gear inches
Class reference (p10–p90): 17.1–98.6 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Mountain / Trail Model year: 2025
Lowest gear: 1382 bicycles with this information, 74.5% of the class
Highest gear: 1382 bicycles with this information, 74.5% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2025 builds

Differences across 2025 builds
Specification	This bicycle Trek Top Fuel 9.8 Gen 4 GX AXS	Trek Top Fuel 5 Gen 4	Trek Top Fuel 8 Gen 4	Trek Top Fuel 9.8 Gen 4 XT	Trek Top Fuel 9.9 Gen 4 X0 AXS	Trek Top Fuel 9.9 Gen 4 XTR
Frame
Frame material	Carbon	Aluminum	Aluminum	Carbon	Carbon	Carbon
Bicycle weight	13.2 kg	15.9 kg	14.58 kg	13.45 kg	13.1 kg	12.63 kg
Drivetrain
Largest sprocket	52	51	51	51	52	51
Lowest gear	16.7 in	17.1 in	17.1 in	17.1 in	16.7 in	16.2 in
Highest gear	87.0 in	87.0 in	87.0 in	87.0 in	87.0 in	82.5 in
Cockpit
Derailleur hanger	UDH	Not informed	Not informed	Not informed	UDH	Not informed
Shifting	Electronic	Mechanical	Mechanical	Mechanical	Electronic	Mechanical
Other specifications
Wheel material	Aluminum	Aluminum	Aluminum	Aluminum	Carbon	Carbon
Wheel size	27.5″ / 29″	29″	27.5″ / 29″	27.5″ / 29″	27.5″ / 29″	27.5″