Lighter and more performing , the new Sidi mtb sole is made of nylon with PU inserts. The shape of the inserts has been designed for mountain biking, allows for excellent grip , facilitates the dispersion of mud and gives the right stability . The central insert marked by the Sidi writing acts as a non-slip , practical (useful) especially for the less experienced. The toe , the area of greatest wear (especially) when walking, can be replaced using screws and always offers the possibility of mounting crampons to improve traction on particularly muddy terrain. SR17 represents themaximum result in terms of stiffness for pedaling and flexion for walking.