[QUOTE=Dahon.Steve;18622021]The Wikipedia article was biased and had an agenda. It appears the forum members accepted Chester Kyle’s 2% loss in friction as gospel without noticing the study was flawed.......
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One other point should be made. While propelling, a part of the rider's energy is consumed by the clutch's designed-in friction. Even though the wheel might be able to spin an entire minute with the bike upside down and hand cranked, the propelling state consumes energy overcoming the clutch's intended friction. It's not much, and it's tiny with respect to wind resistance (and maybe even tire resistance), but it's there. If there's one design flaw in a coaster brake, this is it.
Whenever someone opens a post saying others have a bias and agenda, I start wondering about theirs.
It's pretty obvious that you're not an IGH or coaster brake fan, which is fine, but there's no need to exaggerate issues to push an agenda.
The last reference to coaster brake clutch drag is an example. It's infinitesimal, in the range of the seal drag on modern BBs and hubs, so nothing to even consider. It's certainly far less than the losses to the gear train which is already accounted for. Clutch drag is also a fixed constant, rather than a percentage of power, so as load increases it's impact lessens.
Nobody claims that IGH and coaster brake are as efficient as direct drive single speed or derailleur. Those who fret over clutch drag might also worry about the added drag imposed by the pulleys and spring chain tension. (both also meaningless).
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