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2019 Specialized Tarmac SL6 Pro vs 2021 Specialized Aethos

The Specialized Aethos size closest to your 54 is the 54. Compare the 54 instead

What changes on the Specialized Aethos

Compared with the Specialized Tarmac SL6 Pro in 54, the Specialized Aethos in 61 places the top of the head tube 68 mm higher and 24 mm further forward, relative to the bottom bracket. Its wheelbase is 39 mm longer, which can contribute to stability at speed.

Frame stack
+68 mm
Higher front end
Frame reach
+24 mm
Longer frame reach
Wheelbase
+39 mm
Longer: steadier at speed
Head angle
+1.0°
Steeper: sharper steering
Chainstays
+5 mm
Longer: more planted

The two frames

2019 Specialized Tarmac SL6 Pro (54) and 2021 Specialized Aethos (61), lined up at the bottom bracketBoth frames drawn to scale. The Specialized Tarmac SL6 Pro is drawn in full with its measurements, and the Specialized Aethos is the colored outline on top.J 973

Specialized Tarmac SL6 Pro, 54Specialized Aethos, 61Drawn to scale and lined up at the bottom bracket.

Geometry side by side

MeasurementSpecialized Tarmac SL6 Pro 54Specialized Aethos 61Difference
Reach384mm408mm+24 mm
Stack544mm612mm+68 mm
Head tube angle73°74°+1.0°
Seat tube angle74°73°−1.0°
Effective top tube540mmnot listed
Chainstay length405mm410mm+5 mm
Wheelbase973mm1012mm+39 mm
BB drop72mm72mm±0 mm
BB height268mm268mm±0 mm
Standover775mm824mm+49 mm
Seat tube length481mm567mm+86 mm
Fork length363mm369mm+6 mm
Head tube length143mm204mm+61 mm

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

Where each sits in its class

Specialized Tarmac SL6 ProSpecialized 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 SL6 ProProSpecialized AethosAethos Frameset
FrameSpecialized Tarmac SL6Specialized Aethos FACT
Seatpostnot listedRoval Alpinist

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