2021 Trek

FX Sport Carbon 4

A 700c carbon frame fitness bike with upper mid-range components and hydraulic disc brakes.

MSRP$1,819
Weight21.1 lbs  
FrameCarbon
SuspensionRigid
ForkCarbon
Wheels700c Aluminum
Drivetrain1 × 11
GroupsetGRX 800, 105
BrakesHydraulic Disc
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Insights
Ride Feel

Based on frame geometry and build specs.

Rider Position
relaxedaggressive
FX Sport Carbon 4
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Gearing

A bike with lower gearing will be easier to ride up steep hills, while a higher top end means it will pedal faster down hills.

Lowest gear

(climbing)

31 mph

FX Sport Carbon 4

35 mph

Similar Bikes

Highest gear

(descending)

Spec Level

Based on build material and quality level of the frame, fork, wheelset, groupset, suspension system, and more.

Sizing
XS

4'9" – 5'2"

SM

5'0" – 5'6"

MD

5'4" – 5'10"

LG

5'8" – 6'2"

XL

6'0" – 6'6"

Rider Fit Notes
  • 5'9", size LG, Just right
Reviews
Cycling News
Trek FX 2 Disc Equipped review: Unspectacular but effective

Sep 2022 · Benjamin Page

The Trek FX 2 Disc is a versatile all-rounder with surprising levels of comfort and stability

Highs
  • The frame has a great balance between responsiveness and comfort

  • Equipped for night riding, bikepacking or commuting

  • Can carry a decent amount of weight

  • Stable ride for long distances

Lows
  • Would need a drivetrain upgrade to become a serious fitness bike

  • On the heavy side for a rigid frame

Read Review

BikeRadar
Trek FX Sport 6 review

Nov 2018 · Ian Osborne

High-class fitness bike with proven road technology and a classy component package. Buy if you want a capable, high-spec yet sensible-handling bike with a flat bar

Highs
  • Comfortable-yet-fun ride, IsoSpeed decoupler, lightweight, Shimano 105

Lows
  • Cost is the biggest one, funky-looking grips, only available in black

Read Review

Geometry
99 Spokes on YouTube99 Spokes on YouTube
Specs
Build
Frame

400 series OCLV carbon, IsoSpeed, internal routing, 3s chain keeper, DuoTrap S compatible, fender mounts, flat mount disc, 142x12mm thru axle

BB StandardBB86/BB92, 86.5mm, Press Fit

Tire Clearance35c

ColorsDark Aquatic / Carbon Smoke; Quicksilver / Carbon Smoke

Fork

FX Carbon, threadless alloy steerer, hidden fender mounts, flat mount disc, 405mm axle-to-crown, 100x12mm thru axle

Bottom Bracket

Shimano BB71, 86.5mm, PressFit

Headset

1-1/8'' threadless, sealed cartridge bearings

Stem

Size: XS, Bontrager Elite, 31.8mm, Blendr compatible, 7 degree, 90mm length; Size: S, M, Bontrager Elite, 31.8mm clamp, Blendr compatible, 7 degree, 100mm length; Size: L, XL, Bontrager Elite, 31.8mm clamp, Blendr compatible, 7 degree, 110mm length

Handlebar

Size: XS, S, Bontrager Satellite Plus IsoZone, alloy, 31.8mm, 15mm rise, 600mm width; Size: M, L, XL, Bontrager Satellite Plus IsoZone, alloy, 31.8mm, 15mm rise, 660mm width

Saddle

Bontrager H1

Seatpost

Bontrager alloy, 27.2mm, 12mm offset, 330mm length

TypeRigid

Pedals

Wellgo M141, resin body, alloy cage

Grips

Bontrager Satellite IsoZone Plus, lock-on, ergonomic

Groupset
Rear Derailleur

Shimano GRX RX812, long cage, 42T max cog

Crank

Size: XS, S, Shimano GRX RX600, 40T ring, 170mm length; Size: M, L, XL, Shimano GRX RX600, 40T ring, 175mm length

Shifters

Shimano RS700, 11 speed

Cassette

Shimano SLX M7000, 11-42, 11 speed

Chain

Shimano HG601

Brakes

Size: XS, S, M, L, XL, Shimano hydraulic disc, MT201 lever, UR300 caliper; Size: XS, S, M, L, XL, Shimano MT201 hydraulic disc, flat mount, 160mm rotor

TypeHydraulic Disc

Wheels
Rims

Bontrager Tubeless Ready Disc, 32-hole, presta valve

Spokes

14g stainless steel

Front Hub

Formula alloy, centerlock disc, 100x12mm thru-axle

Rear Hub

Shimano RXC400, centerlock, Shimano 11-speed freehub, 142x12mm thru axle

Tires

Bontrager R1 Hard-Case Lite, wire bead, 60 tpi, 700x32c

Disc Rotors

Shimano RT10, centerlock, 160mm

Rider Notes
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Last updated April 18