2025 Specialized Tarmac SL8 Ready to Paint vs 2025 Specialized Aethos Pro
The 56 is the Specialized Aethos Pro size closest to your 56 Specialized Tarmac SL8 Ready to Paint. 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 Aethos Pro
Compared with the Specialized Tarmac SL8 Ready to Paint in 56, the Specialized Aethos Pro 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
Specialized Tarmac SL8 Ready to Paint, 56Specialized Aethos Pro, 56Drawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Specialized Tarmac SL8 Ready to Paint 56 | Specialized Aethos Pro 56 | Difference |
|---|---|---|---|
| Reach | 395mm | 395mm | ±0 mm |
| Stack | 565mm | 565mm | ±0 mm |
| Head tube angle | 73.5° | 73.5° | ±0.0° |
| Seat tube angle | 73.5° | 73.5° | ±0.0° |
| Effective top tube | 563mm | 562mm | −1 mm |
| Chainstay length | 410mm | 410mm | ±0 mm |
| Wheelbase | 991mm | 991mm | ±0 mm |
| BB drop | 72mm | 72mm | ±0 mm |
| BB height | 268mm | 268mm | ±0 mm |
| Standover | 786mm | 769mm | −17 mm |
| Seat tube length | 494mm | 504mm | +10 mm |
| Fork length | 370mm | 369mm | −1 mm |
| Head tube length | 157mm | 157mm | ±0 mm |
Differences are the Specialized Aethos Pro minus the Specialized Tarmac SL8 Ready to Paint. Full charts: 2025 Specialized Tarmac SL8 Ready to Paint, 2025 Specialized Aethos Pro.
Where each sits in its class
Specialized Tarmac SL8 Ready to PaintSpecialized Aethos Pro
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 Tarmac SL8 Ready to PaintS-Works Ready to Paint | Specialized Aethos Pro |
|---|---|---|
| Frame | Specialized S-Works Tarmac SL8 FACT | not listed |
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