Praxis Buzz 130BCD Chainring. The Buzz chainring series features cold-forged chainrings, which offer greater hardness and better wear resistance than CNC-machined chainrings. Additionally, this process allows for easy application of LevaTime technology. LevaTime is a unique technique where all teeth have their own specific shape, ensuring that a chain can shift perfectly from the small to the large chainring. Buzz chainrings are available in 110BCD: 46/36, 48/32, 50/34, 52/36 and 130BCD: 53/39 tooth combinations. Suitable for 10, 11, and 12-speed chains. Comes with a replaceable chain retention pin. For optimal shifting performance, it is perfectly suited for use with Di2, EPS, or eTap shifting systems. Compatible with mechanical and electronic shifting systems from Shimano, SRAM, and Campagnolo.