If you are riding Shimano's S-Phyre XC9 or RC9 footwear, and need a cold weather shoe cover, you have to strongly consider the S-Phyre Insulated Shoe Cover, which was conceived, designed, and engineered via their Fusion Concept system to fully integrate with these top performing road and mountain shoes. The flexible, one-piece, pull-on design delivers optimized waterproof protection and comfort in cold and wet training conditions. An added bonus of creating shoes and shoe covers as a system is that the Boa dials are readily accessible and adjustable without removing the covers, making mid-ride fine-tuning not only possible, but easy.

How is it possible to offer a pull-on full height shoe cover that also allows the wearer to adjust the BOA dials of the XC9/RC9 shoes? That starts with materials, which for the main body of the cover consists of a blend of very stretchy, flexible rubber (88%) and polymide (12%), which establishes some parameters while adding strength. The secondary material mix is found in the bottom section, which offers the hole space that you need for for cleat and heel tap. Made to create as effective a seal as possible around the zones, the stretchy material still provides water protection and helps with insulation, keeping the outsole from contact with freezing air.

The design and construction follow the S-Phyre standard of 3D Left Right Anatomic specificity, again in line with the L/R shoe designs as well. The S-Phyre Insulated Shoe Cover is considered fully waterproof due to the materials and seam-sealed construction. form-fitting, wide, stretch top cuff seals out the water from the top. The hydrophilic fabric makes for an easy post-ride mud and debris clean-up. Overall, the highly-stretchable neoprene and zipper-free construction make for comfortable, supportive, aerodynamic fit. The material itself both blocks the elements, but also delivers the heat retention via Shimano's Metallic Thermal tech concept, which reflects heat radiated by the feet back to the airspaces between the shoe and cover, ensuring a consistent warmth.

The Fusion Concept as applied to the Insulated Shoe Cover is different than it's Toe Cover sibling. The latter has an open hole that is positioned perfectly over the Boa dial for direct access. it works great, but that would not be a great idea for a fully waterproof design. The neoprene used is soft and flexible enough so that you can actually operate the the Boa while covered. As an added benefit the main body is also fully reflective when light shines on it, for excellent visibility and enhancement of safety. No doubt all this took some serious engineering, as finding the right level of flexibility both to pull-on a full cover and adjust the Boa dials could not have been easy to balance against proper insulation, fit, and overall durability. That is why Shimano is Shimano. At it's heart and soul it is a system engineering company, and the S-Phyre Insulated Shoe Cover is designed to fully integrate- as a system with S-Phyre footwear. And it is so.