Twelve cogs spanning 10 to 52 teeth give you the range to clean technical climbs without sacrificing top-end speed on descents. The XG-1275 cassette sits in SRAM's GX Eagle tier, delivering the same 520% gear range as the XX1 and X01 versions at a lower price point. The trade-off is weight—steel construction throughout rather than the machined alloy clusters found higher in the lineup.

SRAM's X-Dome architecture pins and rivets the individual cogs into a unified structure that slides onto XD driver bodies as a single unit. This mounting interface differs from traditional freehub splines, so you'll need an XD-compatible rear hub or driver body before running any Eagle cassette. The XD system handles the torque loads of that massive 52-tooth cog better than conventional splined interfaces, and it allows for the 10-tooth small cog that makes the wide range possible without resorting to enormous chainrings.

Steel construction means the XG-1275 handles abuse that would mark up aluminum cogs. If you're riding in gritty conditions, training through winter, or just prefer durability over gram-counting, the full-steel build makes sense. The weight penalty compared to X01 or XX1 cassettes runs around 150 to 200 grams depending on the version, which matters less when you're not pinning race runs.... Read More