Broctoon

Thanks for the link. That is an interesting study, but it has nothing to do with differences between FG and SS drivetrains. I am not surprised that VO2 is affected by cadence; surely there are many other differences in a rider's performance across a range of cadences.

I think we're saying sort of the same thing, but I emphasize the phrase "when you're applying positive power through the crank" as the key qualifier to my claim that your body can't tell the difference between FG and SS. You're focusing on the fact that at very high cadence, there can be performance differences caused by unique characteristics of the two drivetrain types. We are both right in our respective assertions.

To say that "neither of us knows whether the internal work done moving our legs up and down is identical in FG vs SS" is ridiculous within the parameters I noted (legs able to keep up with the crank so positive power is being applied). We absolutely know there is no difference, just as we know that there is no difference in power delivery for a wheel painted black vs. one painted red. I mean, there might be a psychological effect when the rider knows what kind of drivetrain he's on, just as there might be when he knows what color his wheel is. The psychology of FG vs. SS is a separate topic that might make for an interesting discussion.

79pmooney made an interesting observation a few posts up. Some performance differences might appear when pedaling cadence is very close to drivetrain speed, i.e., your legs are almost able to keep up or just barely able to keep up with the bike. Certainly in that special case we'd want to look at delivered power separately from internal power. It's an important fact that riding a bike requires our legs, muscles, and joints to move in a very specific way (because the pedals must follow a circular path).

I'll go back to one point brought up in the original question of whether "there is a significant drop-off for freewheel regarding power transfer above 100 rpm of the crank." Worded in a less awkward way, I think the OP was asking, "Does a rider get less power to the ground on a SS bike than a FG bike at high cadence?" I believe that yes, there is probably less power reaching the ground any time the cadence is so high that the rider struggles to keep up. This is only because the FG forces the rider to try harder at keeping up. If the cadence gets so high that he cannot keep up no matter how hard he tries, then it's actually just the opposite: SS drive gets more power to the ground (zero) compared to FG (negative power). This seems ridiculously obvious. The point I was trying to make a few posts back (which perhaps is likewise so obvious that it didn't need to be stated and therefore caused some misunderstanding) is that SS and FG drivetrains are identical in their function anytime positive force is being applied. To ask whether one type of cog is more efficient at conveying applied power is like asking whether you'll ride faster when there's a leprechaun watching. That was really my point, that there's no mysterious, mechanical advantage or curse attached to either drivetrain type.