US Patent 9493211 Chainring

A bicycle chainring includes a plurality of teeth extending from a periphery of the chainring wherein roots of the plurality of teeth are disposed adjacent the periphery of the chainring. The plurality of teeth include a first group of teeth and a second group of teeth, each of the first group of teeth wider than each of the second group of teeth. At least some of the second group of teeth arranged alternatingly and adjacently between the first group of teeth, and at least some of the first and/or second group of teeth being asymmetric along the chainring circumference.