7-Speed Cassettes

Cassette sprockets do not include the ratchet mechanism - that's part of the hub. Rear sprockets that include the ratchet (that screw on to the wheel complete), are freewheels.

Shimano CS-HG41 Cassette 7sp Acera 11-28

Acera level Shimano 7-speed cassette.

Sprocket Sizes: 11, 13, 15, 18, 21, 24, 28.

Weight: 224g. Shipping Weight: 327g.

Shimano CS-HG50 Deore 7sp Cassette 12-28

Deore level 7-speed cassette.
 Weight: 304g.

SRAM Cassette 7sp PG-730 12-32

A useful set of gear ratios that Shimano doesn't offer in a 7-speed cassette.
 Weight: 300g.