Originally Posted by
Dutch Jazz
Correct me if I'm wrong here; but if you are saying that friction = power lost, doesn't that mean that 45x12 is better than 52x14, because the chain makes contact with fewer teeth. Fewer contact points = less friction = less power losses?
Couple more things to add (my beating a dead horse personality).
Higher cadence is similar to larger rings/cogs. More teeth come into play and the chain tension is lower. (There is more bearing and human movement energy when spinning - a different conversation.).
If you've has a fixie, track bike, tandem sync chain that is too tight (the eccentric adjustment) you may have experienced it is quite hard to spin. I don't know where each friction component comes into play, or how much each contributes but between the chain/gears/bearings and frame flex it is a lot. The tandem sync chain over tension I am very familiar with and the tension that produced lots of friction (20W area) was about the same we'd get putting out 300W.