Originally Posted by
Carbonfiberboy
For a very long, very hilly with a time limit ride like PBP, I'd choose the fastest equipment available to me. Multispeed hubs are not as efficient as derailleur. The difference is small, but it's there.
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A 2% efficiency difference doesn't mean that the bike is 2% slower, but it will be slightly slower particularly on climbs. Depending on whose Garmin it was, there are about 12k meters of climbing, though mostly on rolling hills.
The people doing the efficiency studies usually bought new equipment. And most Rohloff owners will tell you that their hubs got smoother over time. And I think there was some change in the seals that improved how they roll, but on that I am not sure the details or when that occurred.
Is my Rohloff less efficient than a well lubed new derailleur system? It probably is. But I noticed it was running much smoother by the time I did the first oil change. It just seems to get better year after year.
There was a followup to that study that suggested that there was less friction loss than the study you cited.
https://www.hupi.org/HParchive/PDF/hp55/hp55p11-15.pdf
This raises another point, some studies have shown a measurable efficiency loss if jockey wheels (or pulleys) are used for chain tensioning on an IGH system, where sliding dropouts or eccentric bottom brackets have less friction loss.
And a lot of people are using belts on Rohloffs, the friction losses on belt systems starts yet another debate.
Originally Posted by
znomit
How are the gear changing ergonomics?
I do not know what you are asking. Can you be more specific?