Quiver

2025 Specialized Aethos FACT 10r Carbon vs 2026 Specialized Tarmac SL8 Pro Shimano

The 56 is the Specialized Tarmac SL8 Pro Shimano size closest to your 56 Specialized Aethos 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 Tarmac SL8 Pro Shimano

Compared with the Specialized Aethos FACT 10r Carbon in 56, the Specialized Tarmac SL8 Pro Shimano in 56 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 FACT 10r Carbon (56) and 2026 Specialized Tarmac SL8 Pro Shimano (56), lined up at the bottom bracketBoth frames drawn to scale. The Specialized Aethos FACT 10r Carbon is drawn in full with its measurements, and the Specialized Tarmac SL8 Pro Shimano is the colored outline on top.J 991

Specialized Aethos FACT 10r Carbon, 56Specialized Tarmac SL8 Pro Shimano, 56Drawn to scale and lined up at the bottom bracket.

Geometry side by side

MeasurementSpecialized Aethos FACT 10r Carbon 56Specialized Tarmac SL8 Pro Shimano 56Difference
Reach395mm395±0 mm
Stack565mm565±0 mm
Head tube angle73.5°73.5±0.0°
Seat tube angle73.5°73.5±0.0°
Effective top tube562not listed
Chainstay length410mm410±0 mm
Wheelbase991mm991±0 mm
BB drop72mmnot listed
BB height268mmnot listed
Standover769mmnot listed
Seat tube length504mmnot listed
Fork length369mmnot listed
Head tube length157mm157±0 mm

Differences are the Specialized Tarmac SL8 Pro Shimano minus the Specialized Aethos FACT 10r Carbon. Full charts: 2025 Specialized Aethos FACT 10r Carbon, 2026 Specialized Tarmac SL8 Pro Shimano.

Where each sits in its class

Specialized Aethos FACT 10r 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 10r CarbonFACT 10r CarbonSpecialized Tarmac SL8 Pro ShimanoPro - Shimano Ultegra Di2
FrameSpecialized Aethos FACTSpecialized Tarmac SL8
ForkSpecialized FACT CarbonSpecialized FACT 10r
ShifterSRAM Force eTAP AXSShimano Ultegra R8170
DerailleurSRAM Force eTAP AXSShimano Ultegra R8150 Di2
CassetteSRAM ForceShimano Ultegra
ChainSRAM ForceShimano XT M8100
CranksetSRAM Force DUBShimano Ultegra R81000
ChainringSRAM Forcenot listed
Bottom bracketSRAM DUB BSA 68Shimano Threaded BSA
WheelsetRoval Alpinist CL IIRoval Rapide CL III
TireSpecialized S-Works Turbo 2BRSpecialized S-Works Turbo
BrakeSRAM Force eTAP AXSShimano Ultegra R8170
HandlebarSpecialized S-Works Short & ShallowRoval Rapide Cockpit
StemSpecialized Pro SLRoval Rapide Cockpit
GripsSupacaz Super Sticky Kushnot listed
SeatpostRoval AlpinistSpecialized S-Works Tarmac SL8
SaddleSpecialized Body Geometry PowerSpecialized Power Pro
Rotornot listedShimano Ultegra R8170
Bar tapenot listedSupacaz Super Sticky Kush

Know what is on every bike.

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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