The XG-1391 is the flagship cassette in SRAM's new Red XPLR E1 gravel lineup, and it's the piece that unlocks the 13-speed jump on the rest of the group. The cassette runs a 10-46 tooth spread across 13 cogs to cover the sweet spot of gravel gearing so finding the right cadence is effortless. If you're building a 1x13 Red XPLR AXS drivetrain from the ground up, or upgrading a Force XPLR bike to the top-tier cassette, this is the one that pairs with the Red XPLR AXS rear derailleur and Red Flattop chain.

With 13 cogs, this cassette provides a 460% gear range while only weighing 288 grams. The gearing steps are 10-11-12-13-15-17-19-21-24-28-32-38-46, so you get single-tooth jumps through the fast end of the cassette where cadence matters most on pavement transitions and paceline efforts, then progressively wider jumps as you move into the climbing gears. That layout is the argument for going to 13-speed on a 1x drivetrain — you keep the tight racing cadence up top without giving up the bailout gear when the road tilts up.

Compatibility is where you need to pay attention. Like previous generations of SRAM XPLR, this cassette works with SRAM XDR driver bodies , not standard XD or HG freehubs, so your rear wheel needs the longer XDR freehub body to run it. It works with SRAM E1 XPLR AXS rear derailleurs and SRAM Flattop chains — this is not a drop-in replacement for a 12-speed XPLR setup, and it will not shift correctly with older Eagle or Force AXS 12-speed derailleurs. If you're moving from a previous 12-speed XPLR build, plan on replacing the cassette, chain, derailleur, and shifter together.... Read More