Assos GTO Socks S11

The Assos GTO Socks S11 sit at the top of Assos's MILLE endurance sock lineup. GTO — Gran Turismo Omologato, the Italian motorsport term for race-approved — is Assos's designation for the pinnacle of their comfort and endurance category, and it appears across bib shorts, jerseys, and this sock for the same reason: it signals the highest expression of the line. The S11 generation refines the GTO with a lighter, more breathable cuff construction while preserving the sock's two defining qualities: an 18cm cuff height and gently supportive compression that holds up across multi-hour rides.

The construction uses a dual-zone approach, with each section of the sock built for a distinct function. The foot is 80% polyamide and 20% elastane — prioritizing breathability and moisture transport, keeping heat from building inside a snug cycling shoe. The cuff steps up to 72% polyamide and 28% elastane, where the higher elastane content creates the compression and grip that hold the sock in place without restriction. A silicone cuff gripper reinforces this at the top edge, preventing rolling or bunching during sustained efforts, hard climbing, or aggressive accelerations where a lesser sock would begin to slip.

At 18cm (7 inches), the GTO Socks S11 sit at a cuff height that reads as intentional on the bike — proportional with bib shorts that run long or jerseys that ride up, and consistent enough to pair with any kit without overthinking it. Designed for warm weather above 21°C, the sock scores maximum marks for breathability and quick drying on Assos's own rating system. The low-bulk construction fits cleanly inside performance cycling shoes without creating pressure points at the toe box or across the instep. Available in Blackseries, sizes 0 through II.

Specs at a Glance

• Foot composition: 80% Polyamide / 20% Elastane
• Cuff composition: 72% Polyamide / 28% Elastane
• Cuff height: 18cm (7 inches)
• Cuff grip: Silicone gripper
• Temperature: Warm weather — above +21°C
• Breathability: 5/5 | Quick drying: 5/5
• Tier: MILLE GTO — top of Assos endurance sock lineup
• Color: Blackseries
• Sizes: 0 (EU 35–38), I (EU 39–42), II (EU 43–46)

Design Benefits

1. Dual-zone fabric construction: Separate fabric ratios for foot and cuff zones — the foot optimizes breathability and moisture transfer; the cuff increases elastane content for compression and grip, each built for its specific role.
2. Silicone cuff gripper: Prevents the sock from slipping, rolling, or bunching at the cuff during long efforts — maintains fit integrity from the first pedal stroke to the last.
3. S11 cuff redesign: Lighter and more cooling cuff construction vs. the previous GTO generation, without compromising the compression character or 18cm height that define the sock.
4. Low-bulk foot construction: Engineered to sit cleanly inside performance cycling shoes — no pressure points, no bunching, no added volume that disrupts shoe fit.