The React cassette is available for 10- and 11-speed drivetrains, the REACT cassette features proprietary shifting technology that pairs well with KMC and other chains.
Called Flow Control, the REACT cassette features dual shifting ramps for smooth and steady gear changes. The ramped tooth profiles help lift and lower the chain during corresponding shifts, providing excellent shifting performance. The unique tooth profiles are wider to reduce friction and increase durability. KMC optimized the cassette design for KMC chains but it will work well with other brands, as well.
Several ranges of cog sizes are available, including an 11-speed 11-50T and 10-speed 11-42T, allowing riders to not only upgrade their worn drivetrain but also greatly increase their gear range over stock offerings. The cog sizes are gradually increased for smoother shifting and precise chain indexing. The REACT cassette is compatible with a Shimano HG freehub body.
REACT Cassette Range Options:
10-speed: 11-36T, 11-42T
11-speed: 11-42T, 11-50T
See more at KMC.