2025 Specialized Aethos FACT 10r Carbon vs 2026 Specialized Tarmac SL8 Pro Shimano
The Specialized Tarmac SL8 Pro Shimano size closest to your 54 is the 54. Compare the 54 instead
What changes on the Specialized Tarmac SL8 Pro Shimano
Compared with the Specialized Aethos FACT 10r Carbon in 54, the Specialized Tarmac SL8 Pro Shimano in 58 places the top of the head tube 47 mm higher and 18 mm further forward, relative to the bottom bracket.
- Frame stack
- +47 mm
- Higher front end
- Frame reach
- +18 mm
- Longer frame reach
- Wheelbase
- n/a
- One of the bikes has no number for this
- Head angle
- +0.5°
- Steeper: sharper steering
- Chainstays
- ±0 mm
- About the same
The two frames
Only the Specialized Aethos FACT 10r Carbon is drawn. The Specialized Tarmac SL8 Pro Shimano numbers we have for size 58 are missing the wheelbase.
Geometry side by side
| Measurement | Specialized Aethos FACT 10r Carbon 54 | Specialized Tarmac SL8 Pro Shimano 58 | Difference |
|---|---|---|---|
| Reach | 384mm | 402 | +18 mm |
| Stack | 544mm | 591 | +47 mm |
| Head tube angle | 73° | 73.5 | +0.5° |
| Seat tube angle | 74° | 73.5 | −0.5° |
| Effective top tube | 540 | not listed | |
| Chainstay length | 410mm | 410 | ±0 mm |
| Wheelbase | 978mm | not listed | |
| BB drop | 72mm | not listed | |
| BB height | 268mm | not listed | |
| Standover | 748mm | not listed | |
| Seat tube length | 481mm | not listed | |
| Fork length | 369mm | not listed | |
| Head tube length | 137mm | 184 | +47 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
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.
| Part | Specialized Aethos FACT 10r CarbonFACT 10r Carbon | Specialized Tarmac SL8 Pro ShimanoPro - Shimano Ultegra Di2 |
|---|---|---|
| Frame | Specialized Aethos FACT | Specialized Tarmac SL8 |
| Fork | Specialized FACT Carbon | Specialized FACT 10r |
| Shifter | SRAM Force eTAP AXS | Shimano Ultegra R8170 |
| Derailleur | SRAM Force eTAP AXS | Shimano Ultegra R8150 Di2 |
| Cassette | SRAM Force | Shimano Ultegra |
| Chain | SRAM Force | Shimano XT M8100 |
| Crankset | SRAM Force DUB | Shimano Ultegra R81000 |
| Chainring | SRAM Force | not listed |
| Bottom bracket | SRAM DUB BSA 68 | Shimano Threaded BSA |
| Wheelset | Roval Alpinist CL II | Roval Rapide CL III |
| Tire | Specialized S-Works Turbo 2BR | Specialized S-Works Turbo |
| Brake | SRAM Force eTAP AXS | Shimano Ultegra R8170 |
| Handlebar | Specialized S-Works Short & Shallow | Roval Rapide Cockpit |
| Stem | Specialized Pro SL | Roval Rapide Cockpit |
| Grips | Supacaz Super Sticky Kush | not listed |
| Seatpost | Roval Alpinist | Specialized S-Works Tarmac SL8 |
| Saddle | Specialized Body Geometry Power | Specialized Power Pro |
| Rotor | not listed | Shimano Ultegra R8170 |
| Bar tape | not listed | Supacaz Super Sticky Kush |
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