Quiver

2017 Specialized Sirrus Disc vs 2019 Trek FX Sport

The Trek FX Sport size closest to your M is the L. Compare the L instead

What changes on the Trek FX Sport

Compared with the Specialized Sirrus Disc in M, the Trek FX Sport in S places the top of the head tube 42 mm lower and 7 mm further back, relative to the bottom bracket. Its wheelbase is 17 mm shorter, which can contribute to quicker direction changes.

Frame stack
−42 mm
Lower front end
Frame reach
−7 mm
Shorter frame reach
Wheelbase
−17 mm
Shorter: quicker to change direction
Head angle
−1.0°
Slacker: calmer steering
Chainstays
−7 mm
Shorter: livelier

The two frames

2017 Specialized Sirrus Disc (M)The Specialized Sirrus Disc frame drawn to scale.J 1073

Only the Specialized Sirrus Disc is drawn. The Trek FX Sport numbers we have for size S are missing the seat angle.

Geometry side by side

MeasurementSpecialized Sirrus Disc MTrek FX Sport SDifference
Reach402mm395−7 mm
Stack600mm558−42 mm
Head tube angle71.5°70.5°−1.0°
Seat tube angle73.5°not listed
Effective top tube580mm550−30 mm
Chainstay length445mm438−7 mm
Wheelbase1073mm1056−17 mm
BB drop70mm65−5 mm
BB height281mm285+4 mm
Standover786mm712−74 mm
Seat tube length485mm406−79 mm
Fork length410mmnot listed
Head tube length165mm135−30 mm

Differences are the Trek FX Sport minus the Specialized Sirrus Disc. Full charts: 2017 Specialized Sirrus Disc, 2019 Trek FX Sport.

Where each sits in its class

Specialized Sirrus DiscTrek FX Sport

AggressivePositionUpright
CalmSteeringQuick
PlayfulBalancePlanted

Each bike is ranked against the other commuter bikes on Quiver, on frame geometry alone. Not your hand position or ride feel.

What each ships with

The stock build of each bike's first listed trim. Parts that match are dimmed.

PartSpecialized Sirrus DiscDiscTrek FX Sport4
ShifterShimano EF500Shimano Tiagra
DerailleurShimano Tourney, Shimano AltusShimano Tiagra, Shimano RD-4700 Tiagra
ChainKMC X8KMC X10
CranksetSpecialized StoutShimano R460
TireSpecialized Nimbus ReflectBontrager AW1 Hard-Case Lite
SaddleSpecialized Canopy SportBontrager H1
Framenot listedTrek Alpha
Forknot listedTrek FX
Cassettenot listedShimano Tiagra
Brakenot listedShimano MT201
Handlebarnot listedBontrager Satellite Plus IsoZone
Seatpostnot listedBontrager SSR

Know what is on every bike.

Add your bike to Quiver. Keep its parts, setup, and service history together, then share your build.

Explore the app
A Transition Relay build sheet: frame, fork, shock and drivetrainThe Relay’s ride photo galleryThe Relay’s ride spectrum and 2D frame geometryThe garage: five bikes and 99 recorded partsA Specialized Tarmac SL8 road build sheet