On Nov 20, 2009, at 9:52 AM, PATRICK MOORE wrote: > On Fri, Nov 20, 2009 at 8:38 AM, It Depends <dmccu...@gmail.com> > wrote: > Berto's later work suggests much narrower gaps between derailer and > IGH systems. See http://www.ihpva.org/HParchive/PDF/hp52-2001.pdf > (noting especially conclusion 2: "Hub gears are generally about 2% > lower in efficiency than derailleur-type gears. But there are > exceptions.").
> Very interesting: apparently, at least on some hubs, direct drive > is *more* efficient than any gear on a deraileur drivetrain. Not really surprising. The derailleur sends the chain through two jockey wheels which wrap the chain around a tight radius. Those of us who ride fixed gears (no longer me) have probably noticed we can swing a bit taller gear in most situations than we'd be comfortable doing with a derailleur. My guess is that friction losses in wrapping the chain around the jockey wheels and friction in the jockey bearings is why. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=.
