SIDI puts rider fit and performance foremost, and the results speak for themselves. Winning is SIDI's legacy, established by more than 50 years of footwear innovation in the pursuit of performance and helping athletes realize their fullest potential. SIDI - A continuing passion for craftsmanship. Replacement Soles for Sidi SR boots. The SR-SMS sole fits all SR boots from 2006 onwards. Sold in pairs.