2023 Specialized Aethos 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 in 54, the Specialized Tarmac SL8 Expert in 52 places the top of the head tube 17 mm lower and 4 mm further back, relative to the bottom bracket. Its wheelbase is 3 mm shorter, which can contribute to quicker direction changes.
- Frame stack
- −17 mm
- Lower front end
- Frame reach
- −4 mm
- Shorter frame reach
- Wheelbase
- −3 mm
- Shorter: quicker to change direction
- Head angle
- −0.5°
- Slacker: calmer steering
- Chainstays
- ±0 mm
- About the same
The two frames
Specialized Aethos, 54Specialized Tarmac SL8 Expert, 52Drawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Specialized Aethos 54 | Specialized Tarmac SL8 Expert 52 | Difference |
|---|---|---|---|
| Reach | 384mm | 380 | −4 mm |
| Stack | 544mm | 527 | −17 mm |
| Head tube angle | 73° | 72.5 | −0.5° |
| Seat tube angle | 74° | 74 | ±0.0° |
| Chainstay length | 410mm | 410 | ±0 mm |
| Wheelbase | 978mm | 975 | −3 mm |
| BB drop | 72mm | 75 | +3 mm |
| BB height | 268mm | 266 | −2 mm |
| Standover | 748mm | 746 | −2 mm |
| Seat tube length | 481mm | 456 | −25 mm |
| Fork length | 369mm | 370 | +1 mm |
| Head tube length | 137mm | 120 | −17 mm |
Differences are the Specialized Tarmac SL8 Expert minus the Specialized Aethos. Full charts: 2023 Specialized Aethos, 2025 Specialized Tarmac SL8 Expert.
Where each sits in its class
Specialized AethosSpecialized 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 | Specialized Tarmac SL8 ExpertExpert |
|---|---|---|
| Frame | not listed | Specialized Tarmac SL8 FACT |
| Fork | not listed | Specialized FACT 10r Carbon |
| Shifter | not listed | Shimano Ultegra R8170 Di2 |
| Derailleur | not listed | Shimano Ultegra R8150 Di2, Shimano Ultegra R8150 Di2 front |
| Cassette | not listed | Shimano Ultegra |
| Chain | not listed | Shimano Ultegra |
| Crankset | not listed | Shimano Ultegra R8100 |
| Chainring | not listed | Shimano Ultegra |
| Bottom bracket | not listed | Shimano Ultegra |
| Wheelset | not listed | Roval C38 |
| Tire | not listed | Specialized S-Works Turbo |
| Brake | not listed | Shimano Ultegra R8170 Di2, Shimano Ultegra R8170 Di2 rear |
| 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 |
| Seatpost | not listed | Specialized S-Works Tarmac SL8 |
| Saddle | not listed | Specialized Power Expert |
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