Originally Posted by
krispenhartung
That's a good question. ("He" by the way). I was very focused on keeping my pedal stroke consistent across all the test intervals. It occurred on both tests, so what's the chances me repeating the same cadence idiosyncrasy twice on the same test interval in two separate tests and sled configurations? The only other test variable going on there is that it's the only test interval that is only a 5rpm increment, vs. 10 like the rest. Beyond this, I'm mystified.
There are a handful of different ways to spin the cranks depending on what muscles you activate and the timing used. As you progress through the RPMs you may notice that you will actually switch teams of muscles used to turn the cranks, especially in the higher RPMs.
This obviously happens when you go from standing to seated in let's say a standing lap effort. But, it also happens when you do seated cadence drills on rollers/trainer.
115RPM might be where you go from using one set of muscles to another. The boost in power may be the fresh muscles coming into the game.
EDIT:
Also, there is a point where torque and cadence are optimal and there is a boost of power. This happens for many sprinters at around 120RPM when they are doing standing lap, 500M, or Kilo type efforts. They get a big boost of acceleration right there. It's evident in the power files. If you are watching team sprint and see man 1 pull away from the other rider(s) coming out of turn 2, that's when it's happening. This is exactly like the sweet spot in the torque range of a manual transmission car.
Maybe you are hitting that at 115RPM.