The sram x01 eagle 12 speed cassette kills the last dangling shred of an argument in favour of a mountain bike front derailleur designed for use with a xd driver body this 12 speed 10 to 50 tooth cassette offers an optimal 500 gear range at a considerably lighter weight than 2x systems features x dome architecture which independent tests have concluded yields the strongest cassettes on the market new s sram x01 eagle 12 speed cassette features sramrs