Excel Wheels Dirt Bike Motocross Wheels - Excel Colorworks Rear Rim, The Excel Takasago aluminum alloy rim is the benchmark in offroad racing rim technology. Every Excel Motocross rim is engineered and designed to perform in extreme hostile environments where other rims routinely fail. Fact, Excel has won more Motocross and offroad championships - worldwide - than all competitors combined. Part of the secret is in the exclusive 7000 series aluminum alloy which has a 50% higher yield strength than other competitor's 6 series aluminum.