2026 Specialized Aethos 2 vs 2025 Basso SV Shimano Dura Ace
The 51 is the Basso SV Shimano Dura Ace size closest to your 52 Specialized Aethos 2. 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 Basso SV Shimano Dura Ace
Compared with the Specialized Aethos 2 in 52, the Basso SV Shimano Dura Ace in 51 places the top of the head tube 9 mm higher and 3 mm further forward, relative to the bottom bracket.
- Frame stack
- +9 mm
- Higher front end
- Frame reach
- +3 mm
- Longer frame reach
- Wheelbase
- +1 mm
- About the same
- Head angle
- −0.1°
- About the same head angle
- Chainstays
- n/a
- One of the bikes has no number for this
The two frames
Only the Specialized Aethos 2 is drawn. The Basso SV Shimano Dura Ace numbers we have for size 51 are missing the chainstay length.
Geometry side by side
| Measurement | Specialized Aethos 2 52 | Basso SV Shimano Dura Ace 51 | Difference |
|---|---|---|---|
| Reach | 377 | 380 | +3 mm |
| Stack | 538 | 547 | +9 mm |
| Head tube angle | 72.1 | 72 | −0.1° |
| Seat tube angle | 74.5 | 74.7 | +0.2° |
| Effective top tube | 526 | 530 | +4 mm |
| Chainstay length | 410 | not listed | |
| Wheelbase | 981 | 982 | +1 mm |
| BB drop | 76.5 | not listed | |
| Head tube length | 128 | 140 | +12 mm |
| Standover | not listed | 772 | |
| Seat tube length | not listed | 485 |
Differences are the Basso SV Shimano Dura Ace minus the Specialized Aethos 2. Full charts: 2026 Specialized Aethos 2, 2025 Basso SV Shimano Dura Ace.
Where each sits in its class
Specialized Aethos 2Basso SV Shimano Dura Ace
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 2S-Works | Basso SV Shimano Dura AceShimano Dura Ace Di2 |
|---|---|---|
| Frame | Specialized Aethos 2 | Basso SV |
| Shifter | SRAM RED | Shimano Dura-Ace R9270 |
| Derailleur | SRAM Red AXS E1 | Shimano Dura-Ace R9250 |
| Cassette | Shimano Dura-Ace R9200 | Shimano Dura-Ace R9200 |
| Chain | SRAM RED E1 | Shimano Dura-Ace |
| Crankset | SRAM Powermeter Red AXS | Shimano Dura-Ace R9200 |
| Chainring | Shimano Dura-Ace R9200 | Shimano 52, Shimano 36 |
| Bottom bracket | SRAM DUB | Shimano Dura-Ace R9200 |
| Wheelset | Roval Alpinist CLX III | DT Swiss ARC 1100 |
| Tire | Specialized Turbo TLR Race | Continental Grand Prix 5000 |
| Hub | Roval LF21-F | not listed |
| Brake | Shimano Dura-Ace R9200 | Shimano Dura-Ace R9270 |
| Rotor | Shimano Dura-Ace R9200 | Shimano Dura Ace Ice Rotor |
| Handlebar | Roval Alpinist Cockpit II | Basso Fuga Integrated |
| Stem | Roval Alpinist Cockpit II | Basso Fuga Integrated |
| Bar tape | Supacaz Super Sticky Kush | not listed |
| Headset | CeramicSpeed SLT | not listed |
| Seatpost | Roval Alpinist | not listed |
| Saddle | Specialized Power | Selle Italia SLR Superflow |
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