Originally Posted by
Wogsterca
You do realise that the efficiency numbers oft quoted for dérailleur gearing is with a clean system and a straight chain line, however that efficiency drops quickly once you get a little distance on it, so it gets dirty and there is usually less then 3 gears that have a perfectly straight chain line...
Frank Berto's research indicates that chain line angle has little impact on efficiency (see the latest edition of
The Dancing Chain for details).
My commuting bike has an Alfine 8-speed IGH, and a fully enclosed chain. I love it, but the gear range is just slightly too small for touring. Rohloff is too expensive and heavy for me now, but I might well consider the 11-speed IGH for my next touring bike--especially for a packable folder, where derailleurs can sometimes suffer from baggage handlers.