The Shimano S-Phyre RC903 is Shimano's flagship road race shoe, worn across the professional peloton. It is built for riders who want maximum power transfer in sprints and climbs without giving up all-day comfort. The full carbon sole carries Shimano's highest stiffness rating of 12, with a low stack height that keeps your foot close to the pedal axle for a stable, direct feel. The wrap-around upper spreads pressure evenly across the foot, while dual BOA Li2 dials give fine adjustment on the fly. An anti-twist heel stabiliser holds your foot planted through hard efforts. Key features Full carbon composite sole, Shimano rigidity index 12 Dual BOA Li2 dials with micro-adjustment in both directions Surround wrapping upper for even, pressure-free hold Anti-twist heel cup for a locked-in feel Low stack height for pedalling stability Optimised for Shimano SPD-SL cleats Available in standard and wide (E) fits. If you are between sizes or new to S-Phyre, come in for a fitting; the wrap-around closure fits differently to a traditional tongue shoe.