Transmission drivetrains eliminate the derailleur hanger, which means the cassette now handles alignment duties that used to fall on the frame. The XS-1275 GX Eagle T-Type cassette mounts directly to SRAM's XD driver body and positions the cogs precisely where the T-Type derailleur expects them. This isn't just a cassette swap for existing Eagle drivetrains—the entire mounting interface changed when SRAM introduced Transmission, so you'll need the full T-Type ecosystem to run these cogs.

The 10-52 tooth range delivers the same spread as standard Eagle cassettes, giving you a bailout gear for steep climbs and enough top end for descents. SRAM machines the larger cogs from steel and pins them together as a single unit, while the smaller cogs are individual pieces that thread onto the XD driver. This construction method keeps weight reasonable while maintaining the durability you need for trail abuse. The steel construction throughout means these cogs will outlast aluminum alternatives, particularly in gritty conditions where soft metal wears quickly.

Shifting performance ties directly to the cassette's cog profiles and ramp shaping. SRAM designed the tooth geometry specifically for the T-Type derailleur's actuation, so the chain climbs and drops between gears with less hesitation than you'd get mixing components from different generations. The full-steel construction adds weight compared to higher-tier XX and XO cassettes, but it also means you're not babying expensive hardware on rough trails.... Read More