2026 Specialized Aethos 2 Pro vs 2025 Basso SV Shimano Dura Ace

What changes on the Basso SV Shimano Dura Ace

Compared with the Specialized Aethos 2 Pro in 54, the Basso SV Shimano Dura Ace in 51 places the top of the head tube 12 mm lower and 4 mm further back, relative to the bottom bracket. Its wheelbase is 10 mm shorter, which can contribute to quicker direction changes.

Frame stack

−12 mm

Lower front end

Frame reach

−4 mm

Shorter frame reach

Wheelbase

−10 mm

Shorter: quicker to change direction

Head angle

−0.5°

Slacker: calmer steering

Chainstays

n/a

One of the bikes has no number for this

The two frames

Only the Specialized Aethos 2 Pro is drawn. The Basso SV Shimano Dura Ace numbers we have for size 51 are missing the chainstay length.

Geometry side by side

Differences are the Basso SV Shimano Dura Ace minus the Specialized Aethos 2 Pro. Full charts: 2026 Specialized Aethos 2 Pro, 2025 Basso SV Shimano Dura Ace.

Where each sits in its class

Specialized Aethos 2 ProBasso 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.