Originally Posted by
spare_wheel
Isn't wanting an IGH and a "ride fast" commuter a bit of a contradiction. I could see a 2-3 speed hub being a "ride fast" commuter but IGHs have significant efficiency and weight penalties and are not designed for mashing.
According to wikipedia (which references Bicycle Science), IGHs are only a few % to 10% less efficient than a derailleur depending on the condition of the components of derailleur system, what cog you're using, and whether or not you're cross chaining. I think that's acceptable considering the reliability and convenience of the IGH. Besides, my commuting bike rarely takes rides over 8 miles.
When I say "go fast" I don't mean I'm racing to work, I just don't want to be stuck on a bike meant to go ~10 mph when I want to go around 15-20 mph depending on terrain and wind.