Shimano R321 Road Shoe - White The Shimano R321 Road Shoes are designed and engineered for a superb fit, comfort and to maximise pedalling efficiency. Heat mouldable custom-fit technology on upper and insole ensures a performance-enhancing fit. The new design reduces pressure, while increasing aerodynamic advantage due to the smooth inner face. Designed using Teijin Avail, a new ultra-fine synthetic leather that is better suited to Shimano?ÇÖs custom heat-molding process. Once Teijin has been fitted to your foot, it stretches less than Shimanos standard synthetic leather. The anchoring one-way sharks teeth fabric has proven to be a stroke of genius since its addition to Shimanos high-end race shoes. On top of the heel cradle is a soft, smooth border, facilitating comfort and ease of entry.