Quiver

2027 Trek FX vs 2026 Surly Preamble Flat Bar

The S is the Surly Preamble Flat Bar size closest to your XS Trek FX. We match frame stack and reach. This is a geometry comparison, not a fit recommendation; stem, spacers, handlebars and saddle setup also affect your riding position.

What changes on the Surly Preamble Flat Bar

Compared with the Trek FX in XS, the Surly Preamble Flat Bar in S places the top of the head tube 8 mm lower and about as far forward, relative to the bottom bracket. Its wheelbase is 39 mm shorter, which can contribute to quicker direction changes.

Frame stack
−8 mm
Lower front end
Frame reach
−2 mm
About the same reach
Wheelbase
−39 mm
Shorter: quicker to change direction
Head angle
+1.0°
Steeper: sharper steering
Chainstays
−27 mm
Shorter: livelier

The two frames

We can't draw these frames yet. The Trek FX numbers we have for size XS are missing the seat angle. The numbers below still compare.

Geometry side by side

MeasurementTrek FX XSSurly Preamble Flat Bar SDifference
Reach383381−2 mm
Stack543535−8 mm
Head tube angle70.0°71+1.0°
Effective top tube528545+17 mm
Chainstay length447420−27 mm
Wheelbase10521013−39 mm
BB drop6554−11 mm
BB height285not listed
Standover675776+101 mm
Seat tube length330505+175 mm
Head tube length115135+20 mm
Seat tube anglenot listed73
Fork lengthnot listed380

Differences are the Surly Preamble Flat Bar minus the Trek FX. Full charts: 2027 Trek FX, 2026 Surly Preamble Flat Bar.

Where each sits in its class

Trek FXSurly Preamble Flat Bar

AggressivePositionUpright
CalmSteeringQuick
PlayfulBalancePlanted

Each bike is ranked against the other gravel 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.

PartTrek FX2Surly Preamble Flat BarFlat Bar
ForkTrek FXnot listed
ShifterShimano CUES U4000microSHIFT Acolyte Xpress
DerailleurShimano CUES U4000microSHIFT RD-M5185M
CassetteShimano LINKGLIDE LG300not listed
TireBontrager H2 CompKenda Kwik Tendril
RotorTektro Wavenot listed
Framenot listedSurly Preamble
Chainnot listedKMC Z8.3
Brakenot listedAvid BB5
Saddlenot listedSelle Italia X

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