2025 Trek Madone SL Gen 8 Frameset vs 2025 Specialized Aethos Pro
The 49 is the Specialized Aethos Pro size closest to your XS Trek Madone SL Gen 8 Frameset. 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 Trek Madone SL Gen 8 Frameset in XS, the Specialized Aethos Pro in 49 places the top of the head tube 7 mm higher and 5 mm further forward, relative to the bottom bracket.
- Frame stack
- +7 mm
- Higher front end
- Frame reach
- +5 mm
- Longer frame reach
- Wheelbase
- +2 mm
- About the same
- Head angle
- +0.2°
- About the same head angle
- Chainstays
- ±0 mm
- About the same
The two frames
We can't draw these frames yet. The Trek Madone SL Gen 8 Frameset numbers we have for size XS are missing the seat angle. The numbers below still compare.
Geometry side by side
| Measurement | Trek Madone SL Gen 8 Frameset XS | Specialized Aethos Pro 49 | Difference |
|---|---|---|---|
| Reach | 370 | 375mm | +5 mm |
| Stack | 507 | 514mm | +7 mm |
| Head tube angle | 71.6° | 71.75° | +0.2° |
| Effective top tube | 517 | 508mm | −9 mm |
| Chainstay length | 410 | 410mm | ±0 mm |
| Wheelbase | 971 | 973mm | +2 mm |
| BB drop | 72 | 74mm | +2 mm |
| Standover | 704 | 705mm | +1 mm |
| Seat tube length | 404 | 431mm | +27 mm |
| Head tube length | 100 | 109mm | +9 mm |
| Seat tube angle | not listed | 75.5° | |
| BB height | not listed | 266mm | |
| Fork length | not listed | 369mm |
Differences are the Specialized Aethos Pro minus the Trek Madone SL Gen 8 Frameset. Full charts: 2025 Trek Madone SL Gen 8 Frameset, 2025 Specialized Aethos Pro.
Where each sits in its class
Trek Madone SL Gen 8 FramesetSpecialized 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 | Trek Madone SL Gen 8 FramesetSL Gen 8 Frameset | Specialized Aethos Pro |
|---|---|---|
| Fork | Trek Madone Gen 8 | not listed |
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