Quiver

2023 Specialized Aethos LTD 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 LTD in 54, the Specialized Tarmac SL8 Expert 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 40 mm longer, which can contribute to stability at speed.

Frame stack
+68 mm
Higher front end
Frame reach
+24 mm
Longer frame reach
Wheelbase
+40 mm
Longer: steadier at speed
Head angle
+1.0°
Steeper: sharper steering
Chainstays
±0 mm
About the same

The two frames

2023 Specialized Aethos LTD (54) and 2025 Specialized Tarmac SL8 Expert (61), lined up at the bottom bracketBoth frames drawn to scale. The Specialized Aethos LTD is drawn in full with its measurements, and the Specialized Tarmac SL8 Expert is the colored outline on top.J 978

Specialized Aethos LTD, 54Specialized Tarmac SL8 Expert, 61Drawn to scale and lined up at the bottom bracket.

Geometry side by side

MeasurementSpecialized Aethos LTD 54Specialized Tarmac SL8 Expert 61Difference
Reach384mm408+24 mm
Stack544mm612+68 mm
Head tube angle73°74+1.0°
Seat tube angle74°73−1.0°
Chainstay length410mm410±0 mm
Wheelbase978mm1018+40 mm
BB drop72mm72±0 mm
BB height268mm268±0 mm
Standover748mm834+86 mm
Seat tube length481mm545+64 mm
Fork length369mm370+1 mm
Head tube length137mm204+67 mm

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

Where each sits in its class

Specialized Aethos LTDSpecialized 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 LTDS-Works LTDSpecialized Tarmac SL8 ExpertExpert
FrameSpecialized S-Works Aethos FACTSpecialized Tarmac SL8 FACT
ShifterCampagnolo Super RecordShimano Ultegra R8170 Di2
DerailleurCampagnolo Super RecordShimano Ultegra R8150 Di2, Shimano Ultegra R8150 Di2 front
CassetteCampagnolo Super RecordShimano Ultegra
ChainCampagnolo Super RecordShimano Ultegra
CranksetCampagnolo Super RecordShimano Ultegra R8100
WheelsetCampagnolo Hyperon UltraRoval C38
TireSpecialized S-Works Turbo 2BRSpecialized S-Works Turbo
BrakeCampagnolo Super RecordShimano Ultegra R8170 Di2, Shimano Ultegra R8170 Di2 rear
SeatpostRoval AlpinistSpecialized S-Works Tarmac SL8
SaddleSpecialized S-Works PowerSpecialized Power Expert
Forknot listedSpecialized FACT 10r Carbon
Chainringnot listedShimano Ultegra
Bottom bracketnot listedShimano Ultegra
Rotornot listedShimano Ultegra
Handlebarnot listedSpecialized Expert Shallow Drop
Stemnot listedSpecialized Tarmac
Bar tapenot listedSupacaz Super Sticky Kush
Headsetnot listedIntegrated

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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