The shimano dura ace cs 7900 bicycle cassette 10 speed features hyperglide sprockets which have a computer designed tooth configuration with contoured shift gates allowing for smooth shifting even under a heavy load with close ratio gearing for more efficient energy use through improved cadence control the largest sprockets are mounted onto a lightweight alloy carrier to enhance rigidity and reduce weight lm features shimano dura ace cs 7900 bicycle cassette 10 speed computer d