The Synchron Classic features a new compression molded EVA midsole which is current in most modern running shoes. The dual density construction remains true to the original version from the early 1990's. The upper materials have been improved to the premium pigskin suede from synthetic overlays while the original mesh appearance remains true to the era. To modernise the silhouette, Karhu makes the air cushion technology both visible and functional in the outsole. Most importantly, Karhu keeps the unique Synchron Classic lacing structure which served as a way to tighten the forefoot upon repeated use.
The category of shoes known as the Synchron first made their debut in 1980. Easy to recognise by the unorthodox lacing system in the toebox. The research and design team wanted a better fitting upper and came up with the innovative lacing system for added comfort and durability. The Synchron Classic, the 90s edition within the Synchron category, remains a comfortable model featuring an air cushion unit and a stable heel cap.