high-resolution power measurement!

[wallymann]

finally got around to getting this stuff working -- thanks to mr. Clean for the hookup!

will it make me faster? not likely. but still fun to eyeball this stuff on the trainer.

[weisan]

I like to play with this kinda stuff.

Pedaling efficiency - Hmmmm... interesting.

[Mark McM]

Originally Posted by weisan

I like to play with this kinda stuff.

Pedaling efficiency - Hmmmm... interesting.

That measures pedaling effectiveness, not efficiency. Pedaling efficiency is how well a rider's pedaling energy is converted into drivetrain energy. Effectiveness is how well the rider's pedaling forces are converted into drivetrain torque. Generally, effectiveness is a measure of how close the direction of pedal force is to the direction of pedal motion (for example, pushing straight down when the crank is horizontal is 100% effective, whereas pushing straight down when the crank is vertical is 0% effective).

Effectiveness has been measured and studied, but no good correlation has been found between effectiveness and power. In fact, it has been found that when riders concentrate on improving effectiveness, power and efficiency often decrease.

[wallymann]

Originally Posted by Mark McM

In fact, it has been found that when riders concentrate on improving effectiveness, power and efficiency often decrease.

this makes intuitive sense.

it also seems that as one develops and trains a more effective pedalstroke (that can be executed w/o deliberate thought), i suspect that power and efficiency will return and even increase.

[Mark McM]

Originally Posted by wallymann

it also seems that as one develops and trains a more effective pedalstroke (that can be executed w/o deliberate thought), i suspect that power and efficiency will return and even increase.

This hasn't been found to be the case. For example, learning to pull back on the pedal at the bottom of the stroke will increase effectiveness, but this is not an efficient use of the leg muscles. Instead of increasing power and efficiency, it just detracts from being able to use those muscles in their most efficient range of motion.

Here's an excerpt from an article about pedal stroke dynamics:

“For years people always said to pull up as well as push down, and make circles with your legs,” says Tomkinson. “After studying this and performing in-depth analysis of riders’ pedal strokes, I found that this, far from making you better, actually slows you down.”

There's plenty of more information on the subject available.