2019 Specialized Tarmac SL6 Pro vs 2021 Specialized Aethos
The 54 is the Specialized Aethos size closest to your 54 Specialized Tarmac SL6 Pro. 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
Compared with the Specialized Tarmac SL6 Pro in 54, the Specialized Aethos in 54 places the top of the head tube at about the same height and about as far forward, relative to the bottom bracket. Its wheelbase is 5 mm longer, which can contribute to stability at speed.
- Frame stack
- ±0 mm
- About the same height
- Frame reach
- ±0 mm
- About the same reach
- Wheelbase
- +5 mm
- Longer: steadier at speed
- Head angle
- ±0.0°
- About the same head angle
- Chainstays
- +5 mm
- Longer: more planted
The two frames
Specialized Tarmac SL6 Pro, 54Specialized Aethos, 54Drawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Specialized Tarmac SL6 Pro 54 | Specialized Aethos 54 | Difference |
|---|---|---|---|
| Reach | 384mm | 384mm | ±0 mm |
| Stack | 544mm | 544mm | ±0 mm |
| Head tube angle | 73° | 73° | ±0.0° |
| Seat tube angle | 74° | 74° | ±0.0° |
| Effective top tube | 540mm | not listed | |
| Chainstay length | 405mm | 410mm | +5 mm |
| Wheelbase | 973mm | 978mm | +5 mm |
| BB drop | 72mm | 72mm | ±0 mm |
| BB height | 268mm | 268mm | ±0 mm |
| Standover | 775mm | 748mm | −27 mm |
| Seat tube length | 481mm | 481mm | ±0 mm |
| Fork length | 363mm | 369mm | +6 mm |
| Head tube length | 143mm | 137mm | −6 mm |
Differences are the Specialized Aethos minus the Specialized Tarmac SL6 Pro. Full charts: 2019 Specialized Tarmac SL6 Pro, 2021 Specialized Aethos.
Where each sits in its class
Specialized Tarmac SL6 ProSpecialized Aethos
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 SL6 ProPro | Specialized AethosAethos Frameset |
|---|---|---|
| Frame | Specialized Tarmac SL6 | Specialized Aethos FACT |
| Seatpost | not listed | Roval Alpinist |
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