What is the Outsole?

The Outsole is the very bottom layer of the shoe—the tires of your car. It is usually made of durable rubber and is designed to grip the road (or trail) and protect the softer midsole foam from wear and tear.

Types of Rubber

• Blown Rubber: Softer, lighter, and air-injected. Often used in the forefoot for better cushioning.
• Carbon Rubber: Harder and more durable. Typically placed in high-wear areas like the heel.
• Sticky Rubber: Specialized for wet surfaces or trails to prevent slipping.

Tread Patterns

• Road Shoes: Usually flatter with shallow grooves to maximize contact area on pavement.
• Trail Shoes: Feature aggressive lugs (deep cleats) to dig into mud, dirt, and gravel.

Durability

When the outsole rubber wears down to the midsole foam, it's usually a clear sign that the shoe is retired and needs replacing.