Sram: Whether the goal is a finish line, epic adventure or simply getting back home again, our new 900 hubs are ready for the challenge. On the inside, our smooth and durable DOUBLE TIME™ drive mechanism ensures rapid lightning-fast engagement for quick and confident pedal responsiveness. SPEEDBALL™ bearings provide smooth, long-lasting rotation performance. Multiple spoke-count and cassette-capability options, as well as interchangeable end caps make the 900 hubs a perfect choice for any disc-equipped road, gravel, cyclocross, cross country, trail, or enduro bike.