Original shimano parts guarantees that all components work perfectly for optimum performance and maximum safety and longevity features lock in performance with durable construction and robust adjustability versatile gear range supports a broad range of riding styles number of sprockets 11 12 13 14 15 17 19 21 23 25 12 13 14 15 17 19 21 23 25 28 11 12 14 16 18 20 22 25 28 32 11 13 15 17 19 21 23 26 30 34