Quiver

2026 Specialized Tarmac SL8 Pro SRAM vs 2025 Specialized Aethos Pro

The Specialized Aethos Pro size closest to your 54 is the 54. Compare the 54 instead

What changes on the Specialized Aethos Pro

Compared with the Specialized Tarmac SL8 Pro SRAM in 54, the Specialized Aethos Pro in 56 places the top of the head tube 21 mm higher and 11 mm further forward, relative to the bottom bracket. Its wheelbase is 13 mm longer, which can contribute to stability at speed.

Frame stack
+21 mm
Higher front end
Frame reach
+11 mm
Longer frame reach
Wheelbase
+13 mm
Longer: steadier at speed
Head angle
n/a
One of the bikes has no number for this
Chainstays
n/a
One of the bikes has no number for this

The two frames

We can't draw these frames yet. The Specialized Tarmac SL8 Pro SRAM numbers we have for size 54 are missing the head angle, seat angle and chainstay length. The numbers below still compare.

Geometry side by side

MeasurementSpecialized Tarmac SL8 Pro SRAM 54Specialized Aethos Pro 56Difference
Reach384395mm+11 mm
Stack544565mm+21 mm
Effective top tube541562mm+21 mm
Wheelbase978991mm+13 mm
BB height268268mm±0 mm
Seat tube length473504mm+31 mm
Head tube length137157mm+20 mm
Head tube anglenot listed73.5°
Seat tube anglenot listed73.5°
Chainstay lengthnot listed410mm
BB dropnot listed72mm
Standovernot listed769mm
Fork lengthnot listed369mm

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

Where each sits in its class

Specialized Tarmac SL8 Pro SRAMSpecialized Aethos Pro

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 Tarmac SL8 Pro SRAMPro SRAM Force AXSSpecialized Aethos Pro
FrameSpecialized Tarmac SL8not listed
ForkSpecialized FACT 10rnot listed
ShifterSRAM AXS E1 HRD Forcenot listed
DerailleurSRAM AXS E1 Force, SRAM Force AXSnot listed
CassetteSRAM XG-1270 Forcenot listed
ChainSRAM E1 Forcenot listed
CranksetSRAM E1 Forcenot listed
ChainringSRAM Force E1not listed
Bottom bracketSRAM DUBnot listed
WheelsetRoval Rapide CL IIInot listed
TireSpecialized Turbo Race, Specialized Turbo TLR Racenot listed
BrakeSRAM AXS E1 Force, SRAM Force E1not listed
RotorSRAM AXS E1, SRAM 160mm rearnot listed
HandlebarRoval Rapide Cockpitnot listed
StemRoval Rapide Cockpitnot listed
GripsSupacaz Super Sticky Kushnot listed
Bar tapeSupacaz Super Sticky Kushnot listed
SeatpostSpecialized Tarmac SL8 Carbonnot listed
SaddleSpecialized Power Pro Mirrornot listed

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