Quiver

2025 Specialized Aethos LTD vs 2026 Specialized Tarmac SL8 Pro Shimano

The 54 is the Specialized Tarmac SL8 Pro Shimano size closest to your 54 Specialized Aethos LTD. 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 Tarmac SL8 Pro Shimano

Compared with the Specialized Aethos LTD in 54, the Specialized Tarmac SL8 Pro Shimano in 54 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 Aethos LTD (54) and 2026 Specialized Tarmac SL8 Pro Shimano (54), 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 Pro Shimano is the colored outline on top.J 978

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

Geometry side by side

MeasurementSpecialized Aethos LTD 54Specialized Tarmac SL8 Pro Shimano 54Difference
Reach384mm384±0 mm
Stack544mm544±0 mm
Head tube angle73°73±0.0°
Seat tube angle74°74±0.0°
Effective top tube540mmnot listed
Chainstay length410mm410±0 mm
Wheelbase978mm978±0 mm
BB drop72mmnot listed
BB height268mmnot listed
Standover748mmnot listed
Seat tube length481mmnot listed
Fork length369mmnot listed
Head tube length137mm137±0 mm

Differences are the Specialized Tarmac SL8 Pro Shimano minus the Specialized Aethos LTD. Full charts: 2025 Specialized Aethos LTD, 2026 Specialized Tarmac SL8 Pro Shimano.

Where each sits in its class

Specialized Aethos LTDSpecialized Tarmac SL8 Pro Shimano

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 Pro ShimanoPro - Shimano Ultegra Di2
FrameSpecialized S-Works Aethos FACTSpecialized Tarmac SL8
ShifterSRAM RED AXSShimano Ultegra R8170
DerailleurSRAM Red AXSShimano Ultegra R8150 Di2
CassetteSRAM RED XG-1290Shimano Ultegra
ChainSRAM REDShimano XT M8100
CranksetSRAM RED AXS Power MeterShimano Ultegra R81000
Bottom bracketSRAM DUBShimano Threaded BSA
WheelsetRoval Alpinist CLXRoval Rapide CL III
TireSpecialized S-Works Turbo 2BRSpecialized S-Works Turbo
BrakeSRAM Red AXSShimano Ultegra R8170
StemRoval AlpinistRoval Rapide Cockpit
SeatpostRoval AlpinistSpecialized S-Works Tarmac SL8
SaddleSpecialized S-Works PowerSpecialized Power Pro
Forknot listedSpecialized FACT 10r
Rotornot listedShimano Ultegra R8170
Handlebarnot listedRoval Rapide Cockpit
Bar tapenot listedSupacaz Super Sticky Kush

Know what is on every bike.

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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