Originally Posted by
ScottCommutes
The problem is that overrunning clutch (it goes by different names) hidden somewhere in the back of almost everyone's bike.
Hmmm. If you have reliable cadence and speed sensors, you could measure the extent to which this occurs at different cadences.
We know that speed (in km/h) = cadence*60*gear ratio*wheel circumference (in meters)/1000 so if you're "overrunning clutch" if would appear that gear ratio to be
higher lower than it should. Gear ratios are discrete, so small deviations in the computed gear are noticeable. So, pedal first in a way that you don't overrun the "clutch" and secondly pedal in a way that you do. The extent to which calculated gear ratios differ between the first and second cases would be a measurement of the effect you describe.