Hello!
Looking at all the alfine bikes around at the moment, most of the MTB ones have 32/34T upfront, however the shimano alfine chainset comes with 39/45T. Is this simply a difference between intended usages?
I'm unsure of the ranges I would get with both combinations. For a Roadrat, should I get a 39T ? It's going to be used in a flat city (Manchester) but I will take it out into the peaks occasionally.
a 48/18 on a alfine (48T front, 18T sprocket) gives the same gear ratios as a road bike with a 39/53 chainset and 12/27 cassette. So depending on what chainring and sprockets you use (and wheel sizes) the alfine can approximate a wide range of gears ratios. For MTB use a 32/18 on the alfine is about the same as a 32T chainset and 11/34 cassette.
I'm not familiar with road bike gearing, I currently commute on a repurposed MTB with a fairly standard cassette. I find myself mainly using the middle ring and the middle - small cogs on the cassette.
So.. If I was to use a 45T Alfine chainset (seems easiest to get hold of in black) and a 20T sprocket at the back on 700c wheels, what would this be approximating?