Originally Posted by nomadmax

Turns out the night at the Holiday Inn worked for me

Right from the horse's mouth:

"Technically, it would. But when you think of how a drivetrain operates — a chain winding its way over chainrings and then around a cassette, and finally, through the serpentine pulley system of a rear derailleur — the more significant cause of friction is actually the angle the chain reaches as it wraps through the rear derailleur.So by opening up those angles and making them less sharp, the chain can articulate less than it would when it passes around smaller pulley wheels. Voila! Less friction."

“The biggest advantage is friction reduction, or increasing the efficiency of the drivetrain,” says Smith. “There’s a couple of ways the OSPW reduces friction. In other words, it’s part of a system. The biggest factor is the larger pulley wheels. The less amount a chain has to articulate as it engages and disengages the pulley wheels, the less friction is produced. The next thing is on the larger pulley wheels, the bearings spin slower so you don’t have as much drag there.”

https://www.velonews.com/gear/tour-d...ys-should-you/