Whether racing prized machines or building their dreams, the XG-1299 cassette is the ultimate, giving riders an unprecedented 520 percent range thanks to the new 10-52 tooth span. Stronger racers are now free to choose larger chainrings for more top speed, without sacrificing climbing range. More time is spent higher up in the cassette, where athletes' power transfer is most efficient and wear and tear is minimized. Featuring the strongest X-Dome™ architecture in the industry and a proven XD™ driver body, it is also backwards compatible to give riders even more Eagle™ upgrade options for their current bikes. With multiple Olympic, World Cup and World Championship titles, it also fits perfectly with the XX1 Eagle AXS™ compatible components.