SRAM PG-970 9 Speed Cassette 2013
Reliable and durable cassette technology. SRAM's cassette performance is optimized through tooth profile and shift ramp design for quick and positive index shifting.
Pretty much said it in the title. No issues with this cassette. I have used all of the SRAM 9spd cassettes. Functionally they are all very reliable and similar. This one starts getting a bit heavier, so if weight is a concern and you can't stand the extra 54grams go with the 980.