Originally Posted by
hueyhoolihan
don't forget the tire profile, i guessed 32mm.
anyway, here's the
calculator i used. see what you get. i came up with about 114 GI, maybe i screwed up somewhere, wouldn't be the first time (today
)... if so i apologize and stand corrected.
I just based it on a nominal 20" wheel OD so the calculation was 56x20/11 = 101.8 gear-inches
For better accuracy, in reality there are two "20"" wheels used on folding bikes, ISO 406 and ISO 451. Assuming 32 mm tires on either of these the actual outside diameters and high gear gear inches would be:
For ISO 406 rims: 406+(32x2) = 470 mm = 18.5" OD and the high gear would be 18.5x56/11 = 94.2 gear-inches
For ISO 451 rims: 451+(32x2) = 515 mm = 20.3" OD and the high gear would be 20.3x56/11 = 103.3 gear-inches.