SMC x Balena 2nd Collection
The S-Wave Returns
BioCir®Flex steps into a new season.
Balena and Stella McCartney continue their collaboration for Winter 2026, bringing Balena’s BioCir®Flex material to the latest S-Wave Sport trainers.
Following its introduction in the Autumn 2025 collection, BioCir®Flex returns in new seasonal colourways demonstrating how next-generation materials can move beyond experimentation and become part of an evolving commercial product.
The collaboration brings together Stella McCartney’s leadership in responsible luxury with Balena’s material innovation, combining design, performance and a more responsible approach to the materials used in footwear.
For Winter 2026, the S-Wave Sport trainer is reimagined through new colours and finishes while retaining the distinctive sculpted sole made with BioCir® Flex.
Developed to deliver the flexibility, durability and impact absorption required for footwear, BioCir® Flex enables the S-Wave to maintain its performance-led design while reducing reliance on conventional fossil-based materials.
BioCir® Flex is Balena’s next-generation flexible material, developed for demanding applications across footwear, fashion and consumer products.
Made from bio-based feedstocks, the material delivers rubber-like flexibility and TPU-level durability. It is designed to perform throughout the life of a product while offering more responsible pathways at its end of use.
BioCir®Flex is a next-generation material
that combines high-performance capabilities with environmental responsibility