Shimano xtr m9000 11 speed mtb cassetterhythm is the essence of smooth power transfer and proper gear step is the key to maintaining rhythm over varied terrain the xtr cs m9000 11 speed 11 40t cassette is not only the widest range cassette shimano has ever produced but also its most balanced thanks to its rhythm step progression it maintains calculated shock free gear steps from one gear to the next saving you energy and helping you maintain your rhythm on the trail features four carbon f