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2023 Trek Émonda SLR vs 2025 Specialized Aethos Pro

The 49 is the Specialized Aethos Pro size closest to your 47 Trek Émonda SLR. 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 Specialized Aethos Pro

Compared with the Trek Émonda SLR in 47, the Specialized Aethos Pro in 49 places the top of the head tube 7 mm higher and about as far forward, relative to the bottom bracket.

Frame stack
+7 mm
Higher front end
Frame reach
+2 mm
About the same reach
Wheelbase
+1 mm
About the same
Head angle
−0.3°
Slacker: calmer steering
Chainstays
±0 mm
About the same

The two frames

We can't draw these frames yet. The Trek Émonda SLR numbers we have for size 47 are missing the seat angle. The numbers below still compare.

Geometry side by side

MeasurementTrek Émonda SLR 47Specialized Aethos Pro 49Difference
Reach373375mm+2 mm
Stack507514mm+7 mm
Head tube angle72.1°71.75°−0.3°
Effective top tube512508mm−4 mm
Chainstay length410410mm±0 mm
Wheelbase972973mm+1 mm
BB drop7274mm+2 mm
Standover692705mm+13 mm
Seat tube length424431mm+7 mm
Head tube length100109mm+9 mm
Seat tube anglenot listed75.5°
BB heightnot listed266mm
Fork lengthnot listed369mm

Differences are the Specialized Aethos Pro minus the Trek Émonda SLR. Full charts: 2023 Trek Émonda SLR, 2025 Specialized Aethos Pro.

Where each sits in its class

Trek Émonda SLRSpecialized Aethos Pro

AggressivePositionUpright
CalmSteeringQuick
PlayfulBalancePlanted

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

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