Pedaling Efficiency Is Our Eternal Theme
Pushing hard over rolling terrain. Carving perfect high-speed turns through tight switchbacks. Crushing a precipitously steep climb. Sprinting for the town limits sign against your riding buddies. There is something truly special about giving your all on the bike and knowing that every ounce of energy you put in is transformed into pure pedaling power.
To maximize your efforts on the bike and reach that peak performance, Shimano introduces the newly updated, best-in-class RC903 S-PHYRE Road Shoes. Following extensive testing and utilizing a fleet of world-class professional riders, these flagship shoes are the ultimate in elite racing apparel, offering improved comfort, lower weight, and sleeker lines than their predecessor.
Setting out on the ambitious undertaking of making the best road racing shoe for men and women even better, Shimano engineers analyzed advanced pedaling dynamics while also studying a wide variety of rider types and pedaling styles to create its most technologically advanced cycling shoe ever.
Utilizing its proprietary Bikefitting.com pedal analyzer, Shimano engineers examined 3D data to better understand how riders apply pressure throughout the pedal stroke, identifying distinct zones where force is exerted differently across the shoe. They then optimized the new RC903 and women’s RC902W shape and materials to maximize power transfer while maintaining comfort.
Shimano shoe engineers also shaved the shoe's overall weight by 10 grams (from 235g to 225g) while still using premium microfiber leather in the upper construction to maximize breathability. To accomplish this, reinforced mesh and micro-fiber leather materials are layered in different regions to enhance fit, flexibility, rigidity, and ventilation. Additionally, the new RC903's upper construction is more rigid toward the rear of the shoe to hold the foot securely in place, but more flexible and elastic materials are used up front to increase comfort.
Amplifying this slipper-like feel is the BOA Li2 fit system, where two lightweight dials and a new crossover lacing pattern unite to deliver customized micro-adjustability so you can easily tweak fit—even on the fly. The new RC903 also features a new heel cup with a more integrated appearance, and the shoes use Shimano’s unique Dynalast shape to deliver an expanded fit range to accommodate a wider range of foot shapes and sizes, which includes standard sizes from 40-48, plus half sizes from 40-46.5, wide sizes from 40-46, and women’s sizes from 36-44 for the North American market.
Shimano’s research with its Bikeftting.com pedal analyzer also helped clarify how the foot moves within the shoe and where power is lost during movement. The result is a new ultra-secure anti-twist stabilizing heel cup that optimizes fit and foot stability, holding your heel in place to prevent movement during hard efforts. The RC903 also features an ample toe box shape with more room in targeted areas for added comfort while maintaining security and stability.
The RC903W women's S-PHYRE shoe delivers the same premium performance features with aggressive riding in mind but in a refined last shape designed specifically for women. The shoe is lower in volume and has a narrower fit that more closely aligns with women’s foot shapes and contours. The RC903W shoe also features a unique colorway and graphics to set it apart as the premier women’s race shoe across the market.