Quiver

2024 Specialized Aethos FACT 12r Carbon vs 2026 Specialized Tarmac SL8 Pro Shimano

The 61 is the Specialized Tarmac SL8 Pro Shimano size closest to your 61 Specialized Aethos FACT 12r 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 Tarmac SL8 Pro Shimano

Compared with the Specialized Aethos FACT 12r Carbon in 61, the Specialized Tarmac SL8 Pro Shimano in 61 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
n/a
One of the bikes has no number for this
Head angle
±0.0°
About the same head angle
Chainstays
±0 mm
About the same

The two frames

2024 Specialized Aethos FACT 12r Carbon (61)The Specialized Aethos FACT 12r Carbon frame drawn to scale.J 1012

Only the Specialized Aethos FACT 12r Carbon is drawn. The Specialized Tarmac SL8 Pro Shimano numbers we have for size 61 are missing the wheelbase.

Geometry side by side

MeasurementSpecialized Aethos FACT 12r Carbon 61Specialized Tarmac SL8 Pro Shimano 61Difference
Reach408mm408±0 mm
Stack612mm612±0 mm
Head tube angle74°74±0.0°
Seat tube angle73°73±0.0°
Chainstay length410mm410±0 mm
Wheelbase1012mmnot listed
BB drop72mmnot listed
BB height268mmnot listed
Standover824mmnot listed
Seat tube length567mmnot listed
Fork length369mmnot listed
Head tube length204mm204±0 mm

Differences are the Specialized Tarmac SL8 Pro Shimano minus the Specialized Aethos FACT 12r Carbon. Full charts: 2024 Specialized Aethos FACT 12r Carbon, 2026 Specialized Tarmac SL8 Pro Shimano.

Where each sits in its class

Specialized Aethos FACT 12r CarbonSpecialized 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 FACT 12r CarbonS-Works FACT 12r CarbonSpecialized Tarmac SL8 Pro ShimanoPro - Shimano Ultegra Di2
FrameSpecialized S-Works Aethos FACTSpecialized Tarmac SL8
SeatpostRoval AlpinistSpecialized S-Works Tarmac SL8
Forknot listedSpecialized FACT 10r
Shifternot listedShimano Ultegra R8170
Derailleurnot listedShimano Ultegra R8150 Di2
Cassettenot listedShimano Ultegra
Chainnot listedShimano XT M8100
Cranksetnot listedShimano Ultegra R81000
Bottom bracketnot listedShimano Threaded BSA
Wheelsetnot listedRoval Rapide CL III
Tirenot listedSpecialized S-Works Turbo
Brakenot listedShimano Ultegra R8170
Rotornot listedShimano Ultegra R8170
Handlebarnot listedRoval Rapide Cockpit
Stemnot listedRoval Rapide Cockpit
Bar tapenot listedSupacaz Super Sticky Kush
Saddlenot listedSpecialized Power Pro

Know what is on every bike.

Add your bike to Quiver. Keep its parts, setup, and service history together, then share your build.

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