The SH XC90 Shoes are Shimano's purpose designed, cross country race shoe. They're fully heat moldable, which ensures a precise fit, and the Rovenica synthetic leather uppers do a good job of conforming to your foot without stretching out, so you get the same fit over the life of the shoes. The sole is Shimano's carbon fiber XC sole, and is optimized for both fit and power transfer, because if the shoe doesn't fit, putting out watts is the least of your concerns. The shoes are finished off with polyurethane lugs, which is what really separates these shoes from Shimano's high end road shoes. Sometimes you have to walkhikerun with your bike, and these slightly softer lugs keep you from sliding all over the place while you try.