Help me understand Shimano Alfine 11 ratio

[Leoner]

Am I understanding this correctly?


If I run a 42 x 20 gear ratio and the hub ratio in first gear is .527 that would be essentially 1.1067 (about the same as a 34 x 31). Or, if I run a 40 x 20 with a .527 ratio would equate to 1.054 (a little lower than 34 x 32).

On the other end of the spectrum, if I run a 42 x 20 when the ratio is 2.153 that would be 4.5213 (bigger than a 50 x 12).

Is that right?

[rkhatibi]

That looks correct. Also plugged it into a gear calculator which makes it easier to visualize.

http://www.gear-calculator.com/?GR=S...8,32&UF2=2170#

[Leoner]

WOW! That is a super cool way to visualize the changes. Thank you!

[christian]

That visualization really reinforces that there is zero reason to go bigger than 40 on an Alfine chainring. Even 38 might be better. And that gives you a seriously low gear. The crank offerings from Shimano are 39t and 45t... but I don't know what the Shimano recommendation for minimum is.