Small chainrings are simple, but they're not all the same. The best way to insure that your SRAM derailleur system shifts optimally is to keep all the drivetrain components in the SRAM family. This is their Yaw 11-Speed Inner Chainring, which works perfectly with Red and Force 22 systems. The Yaw in the name refers to SRAM's Yaw Front Derailleur, which pivots as it shifts from the small to big rings, and vice versa to keep the derailleur perfectly aligned with the chain. This big ring has been designed with tooth profiles, pins, and ramps to mesh perfectly with the Yaw derailleur and SRAM eleven-speed chains, and create or maintain a flawless shifting system. You might have worn out your old inner ring, or you are mating this big ring to a new spider, or perhaps you're changing chainring sizes. In all cases, SRAM has you covered. This inner ring is available for both 110mm and 130mm bolt circle diameter spiders. The inner rings are designed to work with specific outer rings. The 55 to a 42, 53 to 39, 52 to 36, 50 to 34, and 46 to 36.