If you're building or refreshing a SRAM AXS gravel drivetrain and need the wide-range cassette that made the XPLR platform work in the first place, the XG-1251 is the workhorse option in that ecosystem. It runs 10-44T across 12 cogs for a 440% range — enough bailout for loaded gravel climbs, tight enough at the top end to keep pace on pavement — and it's the cassette that pairs with the original 12-speed XPLR rear derailleurs from Rival, Force, and Red AXS.

The MINI CLUSTER hybrid cassette construction combines four small cogs that are CNC machined out of a single block of billet steel with an additional eight cogs that are individually pinned together. That construction is why the cassette shifts as cleanly as it does under load — the machined mini cluster keeps the tight jumps at the high end precise, and the pinned larger cogs keep weight in check without sacrificing durability. Cog progression runs 10, 11, 13, 15, 17, 19, 21, 24, 28, 32, 38, 44, with the smallest gaps stacked at the fast end where you notice them most.

Compatibility is the thing to get right before you order. This is an XDR driver body cassette, so your rear hub needs an XDR freehub — a standard road XD or Shimano HG driver won't accept it. It's built for SRAM's 12-speed AXS XPLR 1x drivetrains and runs on Flattop chains, which means it won't work with mechanical SRAM road groups, Eagle mountain drivetrains, or any Shimano system. If you're on the newer 13-speed XPLR E1 platform, this isn't your cassette — that one uses the XG-1371 or XG-1351.... Read More