The 12x Chorus cassettes for use with the disc or rim brake groupset. The Chorus groupset is fully compatible with the cassettes from the Record and Super Record 2x12-speed groupsets 11-29 and 11-32 but also introduces a new cassette specification of 11-34. The 11-34 cassette offers cyclists even more versatility and a greater choice and autonomy in terms of available gears. Chorus 12-speed now therefore offers a total of three cassette options: 11-12-13-14-15-16-17-19-21-23-26-29 11-12-13-14-15-16-17-19-22-25-28-32 11-12-13-14-15-16-17-19-22-25-29-34 Technologies Same width as the 11-speed cassette: Totally compatible with wheels and frames. The two bigger sets of three in a single-block piece: It eliminates energy dispersion. Surface treatment: It increases durability and improves smoothness Same-thickness spacers: Ensures error-free fitting Features and Benefits Compatibility: Same width as the 11-speed no need to change or update wheels Smaller spaces: Faster more precise shifting Same spacers: Easy error-free fitting. Sets of three in single-block steel: Stiffness and elimination of power dispersion 25-29-34 set of three available as a spare part Can be converted from the 11-32 cassette Weight: 306g 11-29 version Please Note: The new Chorus 12x 11-34 cassette is not compatible with Record or Super Record 12x groupsets