Quiver

2019 Specialized Tarmac SL6 vs 2021 Specialized Aethos

The 52 is the Specialized Aethos size closest to your 52 Specialized Tarmac SL6. 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

Compared with the Specialized Tarmac SL6 in 52, the Specialized Aethos in 52 places the top of the head tube at about the same height and about as far forward, relative to the bottom bracket. Its wheelbase is 5 mm longer, which can contribute to stability at speed.

Frame stack
±0 mm
About the same height
Frame reach
±0 mm
About the same reach
Wheelbase
+5 mm
Longer: steadier at speed
Head angle
±0.0°
About the same head angle
Chainstays
+5 mm
Longer: more planted

The two frames

2019 Specialized Tarmac SL6 (52) and 2021 Specialized Aethos (52), lined up at the bottom bracketBoth frames drawn to scale. The Specialized Tarmac SL6 is drawn in full with its measurements, and the Specialized Aethos is the colored outline on top.J 970

Specialized Tarmac SL6, 52Specialized Aethos, 52Drawn to scale and lined up at the bottom bracket.

Geometry side by side

MeasurementSpecialized Tarmac SL6 52Specialized Aethos 52Difference
Reach380mm380mm±0 mm
Stack527mm527mm±0 mm
Head tube angle72.5°72.5°±0.0°
Seat tube angle74°74°±0.0°
Effective top tube531mmnot listed
Chainstay length405mm410mm+5 mm
Wheelbase970mm975mm+5 mm
BB drop74mm74mm±0 mm
BB height266mm266mm±0 mm
Standover755mm728mm−27 mm
Seat tube length462mm462mm±0 mm
Fork length363mm369mm+6 mm
Head tube length126mm120mm−6 mm

Differences are the Specialized Aethos minus the Specialized Tarmac SL6. Full charts: 2019 Specialized Tarmac SL6, 2021 Specialized Aethos.

Where each sits in its class

Specialized Tarmac SL6Specialized Aethos

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.

What each ships with

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

PartSpecialized Tarmac SL6S-WorksSpecialized AethosAethos Frameset
FrameSpecialized S-Works Tarmac SL6Specialized Aethos FACT
Seatpostnot listedRoval Alpinist

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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