Replace your old 20"x2.125" bike tire with this great 20"x2.125" Black Cruiser CST241 Bicycle Tire from Sunlite. Sunlite's tires are some of the most popular replacement bike parts on the market, and they are available in about every rim size in current use. Let Monster Scooter Parts be your source for the latest bicycle tires from Sunlite with this 20"x2.125" Black Cruiser CST241 Bicycle Tire.