Ultraz 3/3 FUGU Socks

Ultraz 3/3 FUGU Socks

Assos Ultraz 3/3 FUGU are highly insulating winter cycling socks for rides where cold weather demands no compromise. The wool-textile blend reliably stores heat and remains comfortable even when wet, keeping your feet at a stable temperature during long winter rides. A 31 cm high cuff cleanly overlaps winter tights and closes thermal bridges around the shin, providing noticeable added value especially in Switzerland's changeable Alpine climate. The 160-needle construction hugs seamlessly and with light compression, ensuring nothing shifts or cuts in, even when wearing additional overshoes. This model fits into the Assos climaCode 3/3 range for deep winter and is available from us in two variants.

• Wool blend for high thermoregulation, keeps warm even when wet
• Targeted additional insulation at toes and forefoot
• Seamless 160-needle knitting technique with light support against shifting
• Extra-long 31 cm cuff prevents gaps to tights
• climaCode 3/3 designation for winter use in severe frost
• Optimised for wearing under winter booties for a complete thermal system

Technical Details and Features

The FUGU Socks consist of 53% polyamide, 43% wool and 4% elastane – a blend that balances elasticity, moisture management and insulation performance. The 160-needle construction creates a fine-mesh, seamless surface and homogeneous pressure that reduces blister risk and wrinkle formation. Assos specifically reinforces insulation over the toes and along the front foot area, where riding wind hits hardest. Under overshoes, the wool fibres create micro air pockets that store heat without blocking breathability. The 31 cm cuff increases effective coverage and minimises cold air penetration between sock and tights. Available in Assos sizes 0, I, II for a close-fitting, slip-resistant fit.

Applications and Benefits

These winter socks are made for road cycling, gravel and daily commuter use in the cold season – from flat Seeland loops to windy Albula descents. Combined with winter booties, they create a coherent system that effectively protects the foot zone against convection and maintains comfort stable for hours. The wool content supports odour resistance and stays warm even when road spray or meltwater penetrates the shoe. The Assos climaCode 3/3 clearly signals: this sock is designed for the coldest days in winter layering. Technical articles generally emphasise the advantages of wool socks in winter (warmth-to-weight, comfort in cold, performance under overshoes), which additionally supports the application range of this FUGU variant.

Fit, Variants and Care Instructions

The lightly compressive design keeps the sock in place – ideal during intensive intervals or long base training days when loose material tends to shift. The high cuff ensures a clean transition to winter tights and helps conserve heat in the lower leg. This model is available from us in two variants, so you can optimally coordinate your equipment. For long-lasting enjoyment, we recommend washing the socks according to the care label and keeping them away from direct heat, so the wool fibres retain their thermoregulating properties. The material and construction facts come directly from Assos and are confirmed for the current series.