Quiver

2023 Specialized Aethos Ready to Paint vs 2025 Specialized Tarmac SL8 Expert

The Specialized Tarmac SL8 Expert size closest to your 54 is the 54. Compare the 54 instead

What changes on the Specialized Tarmac SL8 Expert

Compared with the Specialized Aethos Ready to Paint in 54, the Specialized Tarmac SL8 Expert in 44 places the top of the head tube 43 mm lower and 18 mm further back, relative to the bottom bracket. Its wheelbase is 8 mm shorter, which can contribute to quicker direction changes.

Frame stack
−43 mm
Lower front end
Frame reach
−18 mm
Shorter frame reach
Wheelbase
−8 mm
Shorter: quicker to change direction
Head angle
−2.5°
Slacker: calmer steering
Chainstays
±0 mm
About the same

The two frames

2023 Specialized Aethos Ready to Paint (54) and 2025 Specialized Tarmac SL8 Expert (44), lined up at the bottom bracketBoth frames drawn to scale. The Specialized Aethos Ready to Paint is drawn in full with its measurements, and the Specialized Tarmac SL8 Expert is the colored outline on top.J 978

Specialized Aethos Ready to Paint, 54Specialized Tarmac SL8 Expert, 44Drawn to scale and lined up at the bottom bracket.

Geometry side by side

MeasurementSpecialized Aethos Ready to Paint 54Specialized Tarmac SL8 Expert 44Difference
Reach384mm366−18 mm
Stack544mm501−43 mm
Head tube angle73°70.5−2.5°
Seat tube angle74°75.5+1.5°
Chainstay length410mm410±0 mm
Wheelbase978mm970−8 mm
BB drop72mm75+3 mm
BB height268mm266−2 mm
Standover748mm723−25 mm
Seat tube length481mm433−48 mm
Fork length369mm370+1 mm
Head tube length137mm99−38 mm

Differences are the Specialized Tarmac SL8 Expert minus the Specialized Aethos Ready to Paint. Full charts: 2023 Specialized Aethos Ready to Paint, 2025 Specialized Tarmac SL8 Expert.

Where each sits in its class

Specialized Aethos Ready to PaintSpecialized Tarmac SL8 Expert

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 Aethos Ready to PaintS-Works Ready to PaintSpecialized Tarmac SL8 ExpertExpert
FrameSpecialized S-Works Aethos FACTSpecialized Tarmac SL8 FACT
SeatpostRoval AlpinistSpecialized S-Works Tarmac SL8
Forknot listedSpecialized FACT 10r Carbon
Shifternot listedShimano Ultegra R8170 Di2
Derailleurnot listedShimano Ultegra R8150 Di2, Shimano Ultegra R8150 Di2 front
Cassettenot listedShimano Ultegra
Chainnot listedShimano Ultegra
Cranksetnot listedShimano Ultegra R8100
Chainringnot listedShimano Ultegra
Bottom bracketnot listedShimano Ultegra
Wheelsetnot listedRoval C38
Tirenot listedSpecialized S-Works Turbo
Brakenot listedShimano Ultegra R8170 Di2, Shimano Ultegra R8170 Di2 rear
Rotornot listedShimano Ultegra
Handlebarnot listedSpecialized Expert Shallow Drop
Stemnot listedSpecialized Tarmac
Bar tapenot listedSupacaz Super Sticky Kush
Headsetnot listedIntegrated
Saddlenot listedSpecialized Power Expert

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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