SRAM NX Eagle PG-1230 Cassette - 12 Speed 11-50t BlackSRAM NX Eagle PG 1230 Cassette 12 Speed 11 50t Black. The NX Eagle PG 1230 cassette gives riders every bit of the climbing range that the Eagle ecosystem affords with a simple upgrade to splined drive body wheels. Designed to be durable enough to withstand the increased demands of E MTB applications and a perfect solution to heavy duty use and abuse. Eagle technology provides an expanded optimum gear range making you fast on the flats giving you