Sram APEX-1 11-Speed Rear Derailleur Long BlackSRAM's Apex 1 drivetrain provides the gear range and the shifting simplicity to let you simply go where you want. The Apex 1 rear derailleur makes that gearing choice a reality with clean, crisp shifts, thanks to SRAM's X HORIZON geometry and our ROLLER BEARING CLUTCH. Just go: Apex 1 will get you there. Long cage fits up to a 42 tooth cog With CAGE LOCK technology, wheel removal and installation are easier than ever Equipped with Roller Bearing