Originally Posted by
noglider
The English/American way of calculating gears should not be called development because it refers to effective diameter, not movement.
With that said, I think having the three options is a good idea. I don't know what factor they use for diameter to convert to development. It might be something close to 26.5 inches since racing tires are pretty small.
Yeah, unfortunately (as I'm sure you know) how we calculate gears in the US is using "27 inches" which is left over when when wheels were actually 27 inches. The reason it still works is that the values are relative to each other. Which brings us to the "Actual Gear Inches vs Nominal Gear Inches" debate. I have never met a trackie that uses actual gear inches when they speak or in their personal calculations. Everyone still uses inches (using 27), ratio, or meters.
But, I could be wrong (as I often am).