For a flat course, a gearing ratio of approximately 2.3:1 is pretty ideal, but on our course people race anywhere from 2.2 to 2.6 successfully. Are you a spinner? Go with a low ratio. Are you a masher? Get closer to 3:1. Always a compromise... TL, DR: go with a 40-17 (2.35:1).
A note on aesthetics: in this author's strong opinion, a small-chainring/small-cog combo looks better than a large-chainring/large-cog combo (which can achieve the same ratio). A 40-17 looks good and works with a 130BCD crank. If you have a 110BCD crank, you could go with a smaller chainring and cog, such as a 34-15 (2.27:1) or 36-15 (2.40:1). Those would look good.
The smallest chainring that will fit a 144BCD (track-specific) crank is 41-tooth; a 130BCD crank can take a 38-tooth; a 110BCD crank can go as small as 33-tooth.
©1978-2023 Fiesta Island Tracklocross Association - A non-real entity with no legal standing.
