Summary:
Climbing shoes are the most versatile part of a climbers quiver of gear. Climbing shoes are specifically designed to be form fitting and provide maximum friction between the feet and the rock. Companies that develop climbing shoes utilize different compounds of rubber that vary in how stiff or flexible the rubber is. The different rubbers provide a variety of advantages and disadvantages depending on the rock type, steepness, and features on the route.
How Friction is generated
Friction generated by the feet is arguably the most crucial component of a climber moving upwards on a climb. This type of movement is largely dominated by the foots ability to have stability on small holds and is dominated by the ideas of static dynamic friction:
F= µR
F = Friction
µ = coefficient of friction (COF) (note that this will vary depending on the rock type being climbed on)
R = resultant force
Rubber shoes are able to generate friction in three distinct ways: deformation, adhesion, and wear.
Deformation occurs by pressing rubber on the rock and deforming the shape of the rubber shoe by the rock crystals. The more pressure applied on the rubber gives more penetration and thus more stability to the foot placement.
Adhesion refers to the direct contact area when the foot is applied to the rock. This type of friction is vastly diminished when other surface particles are between the rock and the rubber such as dirt and water.
Wear refers to the gradual deterioration of the rubber on the shoe generated by continual use. As the shoe is shaved, this creates another form of friction which is ideally avoided in climbing as it results in eventually needing to replace the shoes.
F= µR
F = Friction
µ = coefficient of friction (COF) (note that this will vary depending on the rock type being climbed on)
R = resultant force
Rubber shoes are able to generate friction in three distinct ways: deformation, adhesion, and wear.
Deformation occurs by pressing rubber on the rock and deforming the shape of the rubber shoe by the rock crystals. The more pressure applied on the rubber gives more penetration and thus more stability to the foot placement.
Adhesion refers to the direct contact area when the foot is applied to the rock. This type of friction is vastly diminished when other surface particles are between the rock and the rubber such as dirt and water.
Wear refers to the gradual deterioration of the rubber on the shoe generated by continual use. As the shoe is shaved, this creates another form of friction which is ideally avoided in climbing as it results in eventually needing to replace the shoes.
Soft rubber:
Soft climbing rubber shoes are designed such that there is minimal rubber between the foot and the rock. This provides extreme sensistivty to a climber's feet placement and allows for greater conformation of the rubber shoe to fit onto the shape of the rocks foot hold.
Stiff rubber:
Stiff climbing rubber shoes have thick mid-sole and sole rubbers which allow a more rigid platform for a climber to stabilize with. This thicker rubber will lead to a decrease in sensitivity in feeling the texture of rock but will allow for added composure when attempting to stand on the smallest of hold.
