Fastest XC Wheels In the Real World 1240 grams is an obscenely light weight when talking about mountain bike wheelsets, the kind of weight that XC racers dream about. But light weight alone is no longer enough. So, we engineered the new Control SL wheels to be sharp handling, smooth riding, extra durable, and 22% less likely to pinch-flat your tires, in addition to being some of the lightest weight production wheels on the planet.