2023 Specialized Aethos Comp vs 2025 Specialized Tarmac SL8 Expert
The Specialized Tarmac SL8 Expert size closest to your 54 is the 54. Compare the 54 instead
What changes on the Specialized Tarmac SL8 Expert
Compared with the Specialized Aethos Comp in 54, the Specialized Tarmac SL8 Expert in 44 places the top of the head tube 43 mm lower and 18 mm further back, relative to the bottom bracket. Its wheelbase is 8 mm shorter, which can contribute to quicker direction changes.
- Frame stack
- −43 mm
- Lower front end
- Frame reach
- −18 mm
- Shorter frame reach
- Wheelbase
- −8 mm
- Shorter: quicker to change direction
- Head angle
- −2.5°
- Slacker: calmer steering
- Chainstays
- ±0 mm
- About the same
The two frames
Specialized Aethos Comp, 54Specialized Tarmac SL8 Expert, 44Drawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Specialized Aethos Comp 54 | Specialized Tarmac SL8 Expert 44 | Difference |
|---|---|---|---|
| Reach | 384mm | 366 | −18 mm |
| Stack | 544mm | 501 | −43 mm |
| Head tube angle | 73° | 70.5 | −2.5° |
| Seat tube angle | 74° | 75.5 | +1.5° |
| Chainstay length | 410mm | 410 | ±0 mm |
| Wheelbase | 978mm | 970 | −8 mm |
| BB drop | 72mm | 75 | +3 mm |
| BB height | 268mm | 266 | −2 mm |
| Standover | 748mm | 723 | −25 mm |
| Seat tube length | 481mm | 433 | −48 mm |
| Fork length | 369mm | 370 | +1 mm |
| Head tube length | 137mm | 99 | −38 mm |
Differences are the Specialized Tarmac SL8 Expert minus the Specialized Aethos Comp. Full charts: 2023 Specialized Aethos Comp, 2025 Specialized Tarmac SL8 Expert.
Where each sits in its class
Specialized Aethos CompSpecialized Tarmac SL8 Expert
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 CompComp | Specialized Tarmac SL8 ExpertExpert |
|---|---|---|
| Frame | Specialized Aethos FACT | Specialized Tarmac SL8 FACT |
| Shifter | Shimano 105 R7170 Di2 | Shimano Ultegra R8170 Di2 |
| Derailleur | Shimano 105 R7150 Di2 | Shimano Ultegra R8150 Di2, Shimano Ultegra R8150 Di2 front |
| Cassette | Shimano 105 | Shimano Ultegra |
| Chain | Shimano SLX M7100 | Shimano Ultegra |
| Crankset | Specialized FC-R7100 | Shimano Ultegra R8100 |
| Wheelset | DT Swiss R470 | Roval C38 |
| Tire | Specialized Turbo Pro | Specialized S-Works Turbo |
| Brake | Shimano 105 R7170 | Shimano Ultegra R8170 Di2, Shimano Ultegra R8170 Di2 rear |
| Seatpost | Roval Alpinist | Specialized S-Works Tarmac SL8 |
| Saddle | Specialized Power Sport | Specialized Power Expert |
| Fork | not listed | Specialized FACT 10r Carbon |
| Chainring | not listed | Shimano Ultegra |
| Bottom bracket | not listed | Shimano Ultegra |
| Rotor | not listed | Shimano Ultegra |
| Handlebar | not listed | Specialized Expert Shallow Drop |
| Stem | not listed | Specialized Tarmac |
| Bar tape | not listed | Supacaz Super Sticky Kush |
| Headset | not listed | Integrated |
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