Use gain ratio instead, problem confounded.
Gear inches properly calculated accounts for rim and Tyre size.
Gain is only relevant if you're changing the crank length at the same time.
@Emyr started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Gear inches properly calculated accounts for rim and Tyre size.
Gain is only relevant if you're changing the crank length at the same time.