Trek Top Fuel 8 Gen 4

Name: Trek Top Fuel 8 Gen 4
Brand: Trek

2025 MountainTrail Manufacturer page

Trek Top Fuel 8 Gen 4, color Matte Dark Web

Last known price: $3,999

Prices shown first for United States
Travel: 130 / 120 mm Fork / rear shock
Wheels: 27.5″, 29″
Drivetrain: 1 × 12 30t / 10–51t
Gear range: 510%
Weight: 14.58 kg 32.1 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM High 155–166
SM Low 155–166
MD High 164–176
MD Low 164–176
MD/LG High 173–180
MD/LG Low 173–180
LG High 177–189
LG Low 177–189
XL High 187–195
XL Low 187–195

Components

17 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

Alpha Platinum Aluminum, 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

Bottom bracket
- Shimano BB-MT501
BB-MT501
Cassette
- Shimano SLX CS-M7100-12 12 speeds 10–51t
CS-M7100-12
Chain
- Shimano SLX CN-M7100
CN-M7100
Crankset
- Shimano Deore FC-M6120 12 speeds 30t
FC-M6120
Rear derailleur
- Shimano Deore XT RD-M8100-SGS 12 speeds
RD-M8100-SGS
Shifters
- Shimano Deore XT SL-M8100
SL-M8100

Brakes

2 parts

Wheels and tires

2 parts

Cockpit and contact points

5 parts

Sizes and geometry

10 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size MD/LG High

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	716	716	755	755	772	772	789	789	827	828
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	755	750	760	755	765	760
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: Aluminum
Bicycle weight: 14.58 kg

32.1 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: 51
Lowest gear: 17.1 in
Highest gear: 87.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Dropper seatpost
Shifting: Mechanical

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

17.1 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

Mechanical

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: 6.5 km/h
Highest gear: 33.3 km/h

Total gear range 510%

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: 17.1–87.0 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 8 Gen 4	Trek Top Fuel 5 Gen 4	Trek Top Fuel 9.8 Gen 4 GX AXS	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	Aluminum	Aluminum	Carbon	Carbon	Carbon	Carbon
Bicycle weight	14.58 kg	15.9 kg	13.2 kg	13.45 kg	13.1 kg	12.63 kg
Drivetrain
Largest sprocket	51	51	52	51	52	51
Lowest gear	17.1 in	17.1 in	16.7 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
Shifting	Mechanical	Mechanical	Electronic	Mechanical	Electronic	Mechanical
Derailleur hanger	Not informed	Not informed	UDH	Not informed	UDH	Not informed
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″