What are sealed cassette hubs?

Sealed cassette hubs are bicycle hubs that feature a sealed design to protect the internal components from dirt, moisture, and debris, enhancing longevity and performance. These hubs typically house the cassette, which is the set of gears on the rear wheel, and use sealed bearings for smooth rotation. This design reduces maintenance needs and increases reliability, making them popular among cyclists who ride in various conditions. Overall, sealed cassette hubs contribute to a more efficient and durable cycling experience.