Quiver

2025 Specialized Tarmac SL8 FACT 10r Carbon vs 2025 Specialized Aethos Pro

The 52 is the Specialized Aethos Pro size closest to your 52 Specialized Tarmac SL8 FACT 10r Carbon. 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 Specialized Tarmac SL8 FACT 10r Carbon in 52, the Specialized Aethos Pro in 52 places the top of the head tube at about the same height and about as far forward, relative to the bottom bracket.

Frame stack
±0 mm
About the same height
Frame reach
±0 mm
About the same reach
Wheelbase
±0 mm
About the same
Head angle
±0.0°
About the same head angle
Chainstays
±0 mm
About the same

The two frames

2025 Specialized Tarmac SL8 FACT 10r Carbon (52) and 2025 Specialized Aethos Pro (52), lined up at the bottom bracketBoth frames drawn to scale. The Specialized Tarmac SL8 FACT 10r Carbon is drawn in full with its measurements, and the Specialized Aethos Pro is the colored outline on top.J 975

Specialized Tarmac SL8 FACT 10r Carbon, 52Specialized Aethos Pro, 52Drawn to scale and lined up at the bottom bracket.

Geometry side by side

MeasurementSpecialized Tarmac SL8 FACT 10r Carbon 52Specialized Aethos Pro 52Difference
Reach380mm380mm±0 mm
Stack527mm527mm±0 mm
Head tube angle72.5°72.5°±0.0°
Seat tube angle74°74°±0.0°
Chainstay length410mm410mm±0 mm
Wheelbase975mm975mm±0 mm
BB drop74mm74mm±0 mm
BB height266mm266mm±0 mm
Standover746mm728mm−18 mm
Seat tube length456mm462mm+6 mm
Fork length370mm369mm−1 mm
Head tube length120mm120mm±0 mm
Effective top tubenot listed531mm

Differences are the Specialized Aethos Pro minus the Specialized Tarmac SL8 FACT 10r Carbon. Full charts: 2025 Specialized Tarmac SL8 FACT 10r Carbon, 2025 Specialized Aethos Pro.

Where each sits in its class

Specialized Tarmac SL8 FACT 10r CarbonSpecialized 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.

What each ships with

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

PartSpecialized Tarmac SL8 FACT 10r CarbonFACT 10r CarbonSpecialized Aethos Pro
FrameSpecialized Tarmac SL8 FACTnot listed
SeatpostSpecialized S-Works Tarmac SL8not listed

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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