Tire compounds are essentially mixtures of natural rubbers, synthetic rubbers, silica, carbon, and a few other select ingredients. Tires can be made cheaper by using more synthetic rubber as it is less expensive to buy and easier to manufacture, but this is what makes some tires feel plasticky, appear overly shiny, and yield poor traction performance. There are many trademarked buzzwords around tire compounds, but the reality is that a higher content of natural rubber yields a better performing tire, and high natural rubber is the common feature in high-end tires as well as every single Terrene tire.
Tires with harder rubber compounds will tend to have better resistance to wear and lower rolling resistance, but will have diminished traction as a result. Tires with softer compounds will have superior traction but higher rolling resistance and worse resistance to wear. To make a good combination, dual compound is adopted for high-end tires. The harder compound is in the center for better wear resistance and lower rolling resistance, whereas the soft compound is used in the shoulder area to earn better traction when cornering. For this reason, all of our mountain tires feature dual compounds and we have added proprietary silica in our softer rubber compounds to effectively lower the durometer and increase the traction of a tire as the tire experiences riding friction.
When air temperature gets low, the compound hardness of a tire will be raised and it will lose traction causing the tire to perform poorly in winter riding conditions. As a result, our winter compound tires use a different ratio and type of synthetic/natural rubber. We also add Butadiene rubber to our winter tire compounds to combat these lower temperatures, making the rubber more cold resistant and increasing performance over other tires in similar temperatures.