Trek FX 3 Gen 4

Name: Trek FX 3 Gen 4
Brand: Trek

2025 UrbanFitness Manufacturer page

Last known price: $1,149

Prices shown first for United States
Suspension: Rigid
Wheels: 700c
Drivetrain: 1 × 10 40t / 11–48t
Gear range: 436%
Weight: 11.5 kg 25.4 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

45cm Not informed
50cm 120+
55cm Not informed
60cm Not informed
65cm Not informed

Components

17 of 19 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 Gold Aluminum, internal cable routing, rack & fender mounts, post mount disc, kickstand mount, 135x5mm QR Not identified

Suspension

1 part

Fork

FX carbon, flat-mount disc, rack mounts, 410mm axle-to-crown, ThruSkew 5mm QR Not identified

Drivetrain

5 parts

Cassette
- Shimano CS-LG300-10 10 speeds
CS-LG300-10
Chain
- Shimano CN-LG500
CN-LG500
Crankset
- Prowheel 40t
Rear derailleur
- Shimano Cues RD-U6000 11 speeds
RD-U6000
Shifters
- Shimano Cues SL-U6000
SL-U6000

Brakes

2 parts

Wheels and tires

4 parts

Cockpit and contact points

6 parts

Sizes and geometry

5 sizes Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 55cm

Table

Reach 399mm

Stack 620mm

Wheelbase 1080mm

Head angle 71.5°

Seat angle 73.5°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 700c wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 5 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	385	393	399	409	416
Stackmm	568	594	620	648	673
Top tube lengthmm	543	563	583	613	635
Seat tube lengthmm	375	420	465	520	585
Head tube lengthmm	140	165	190	215	240
Head tube angle	70.5°	71°	71.5°	72.5°	73°
Seat tube angle	74.5°	74°	73.5°	72.5°	72°
Chainstay lengthmm	447	447	447	447	447
Wheelbasemm	1059	1070	1080	1087	1097
Front centermm	620	631	641	648	658
Bottom bracket dropmm	65	65	65	65	65
Standover heightmm	715	754	791	836	884
Fork rakemm	51	50	50	50	51
Trailmm	71	68	64	58	55
Stack/reach ratio	1.48	1.51	1.55	1.58	1.62

Not published by the manufacturer: Bottom bracket height, 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
Fork material: Carbon
Bicycle weight: 11.5 kg

25.4 lb
Weight limit: 136 kg

299.8 lb

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 40
Largest chainring: 40
Rear sprockets: 10
Smallest sprocket: 11
Largest sprocket: 48
Lowest gear: 24.2 in
Highest gear: 105.5 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Tire clearance: Maximum tire width: 40c; Additional specification: Wheel kind: 700
Tire width: 35c
Travel: Front: Additional specification: Not available: Yes
Rear: Additional specification: Not available: Yes
Wheel material: Aluminum
Wheel size: 700c

Technical analysis

3 measures

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

Lowest gear

24.2 gear inches

This value is within the central range for this class.

Cohort: Urban / Fitness Model year: 2025
Sample: 230 bicycles with this information
Coverage: 81.8% of the class

Highest gear

105.5 gear inches

This value is within the central range for this class.

Cohort: Urban / Fitness Model year: 2025
Sample: 230 bicycles with this information
Coverage: 81.8% of the class

Shifting

Mechanical

13 of 281 bicycles with this information use electronic shifting.

Cohort: Urban / Fitness Model year: 2025
Sample: 281 bicycles with this information
Coverage: 100.0% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 9.3 km/h
Highest gear: 40.4 km/h

Total gear range 436%

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: 24.2–105.5 gear inches
Class reference (p10–p90): 21.8–131.8 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Urban / Fitness Model year: 2025
Lowest gear: 230 bicycles with this information, 81.8% of the class
Highest gear: 230 bicycles with this information, 81.8% 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 FX 3 Gen 4	Trek FX 1 Gen 4	Trek FX 2 Equipped	Trek FX 2 Equipped Mid-step	Trek FX 2 Equipped Midstep	Trek FX 2 Equipped Stagger
Frame
Intended fit	Unisex	Unisex	Unisex	womens	womens	womens
Fork material	Carbon	Steel	Aluminum	Aluminum	Aluminum	Aluminum
Bicycle weight	11.5 kg	13 kg	13.8 kg	13.6 kg	13.6 kg	Not informed
Drivetrain
Front chainrings	1	2	1	1	1	1
Smallest chainring	40	30	40	40	40	40
Largest chainring	40	46	40	40	40	40
Rear sprockets	10	8	9	9	9	9
Smallest sprocket	11	12	11	11	11	11
Largest sprocket	48	32	46	46	46	46
Lowest gear	24.2 in	27.2 in	25.2 in	25.2 in	25.2 in	25.2 in
Highest gear	105.5 in	111.2 in	105.5 in	105.5 in	105.5 in	105.5 in
Brakes
Brake type	Hydraulic disc	Mechanical disc	Hydraulic disc	Hydraulic disc	Hydraulic disc	Hydraulic disc
Other specifications
Wheel material	Aluminum	Aluminum	Aluminum	Not informed	Not informed	Not informed