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 .