According to the Shimano web site the Alfine 11 has a ratio range of 0.527 to 2.153 and can take sprockets various sprockets with between 18 and 23 teeth.

So, am I right in thinking that (for example) if an Alfine 11 was set up with a 32t chainring and a 23t sprocket you’d get a ratio range of 0.733 (0.527 * 32 / 23) to 2.995 (2.153 * 32 / 23)?

In comparison a 2×9 gear setup with 22/33 chainrings and a 11-34 cassette would have ratios from 0.688 (22/32) to 2.909 (32/16). So it would have a wider range, but only just.

Have I got my maths the right way round here?

to speed things up:

http://www.sheldonbrown.com/gears/

has alfine 11 in the drop down

Sounds right.

When is the 11 speed Alfine out? Or is it now?

I thought only 18 and 20t sprockets were actually available though?

Alfine sprockets are only in 18 and 20T but you can use Nexus ones (no guides on them) which run from 16 to 23T.

What rootes1 said. ^^
If you want to know anything about gearing, just put the numbers in and see how it compares with what you’ve already got.

Thanks for checking my working. 🙂

I only picked the 23t sprocket as it produced numbers that were easily comparable to the 22/32 & 11-32 ratios.