You know the old saying: All good things come to an end. This includes the life of your mountain bike cassette. Over time, you may notice the teeth of your cassette begin to get rounded. This is a good sign that it's time for a new cassette. If you're looking for a 7-, 8- or 9-speed cassette, we got you covered. A new mtb cassette will breathe new life into your bike's drivetrain (and your riding).