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Jul
21
revised What is the optimal cadence?
added 203 characters in body
Jul
21
comment What's the lowest safe cadence on a climb?
Does the section labeled "Cadence and knee strain" in this bicycles.stackexchange answer address your question? bicycles.stackexchange.com/questions/12518/…
Jul
16
awarded  Nice Answer
Jul
13
comment How do I train for climbing in a relatively flat area?
There is insufficient information to give a good answer. Are you trying to race up these climbs, or are you just trying to survive up these climbs? How long and how steep are the most difficult climbs you anticipate doing? Will you be riding with others with whom you're trying to keep up, or can you set your own pace?
Jul
12
comment When Mark Cavendish says he's sprints at 1500 watts how long is that for?
Cavendish was the subject of Menaspa's 2013 article in IJSPP so it is particularly on point for this question.
Jul
11
revised Analysis of Stages high-speed data
linked to Kautz pedaling data showing one torque peak per revolution
Jul
11
reviewed Approve Shifters compatible with: SG-3D55 (Shimano Nexus 3 speed - disk brake - internal gear hub)
Jul
10
awarded  Informed
Jul
9
comment Analysis of Stages high-speed data
Welcome to bicycles.stackexchange, Andy.
Jul
8
revised Analysis of Stages high-speed data
deleted 22 characters in body
Jul
8
revised Analysis of Stages high-speed data
Describe why exact crank angle is unneeded, and describe algorithm to find peaks.
Jul
7
revised Analysis of Stages high-speed data
added 321 characters in body
Jul
7
comment Analysis of Stages high-speed data
@Oscar The negative parts do reflect counter-acting torque but it appears dbr may have been coasting at the time rather than pedaling. I included the calculation just to show the anomaly. If I were were doing this in "production mode" I would almost certainly record that as zero power, and tine-tune the analytical algorithm to produce average power over a second rather than over a crank revolution.
Jul
7
revised Analysis of Stages high-speed data
added 131 characters in body
Jul
7
answered Analysis of Stages high-speed data
Jul
7
comment What is the effect of changing length of crank arms?
It's been studied quite a bit but usually from the perspective of muscle shortening speed so searching for "crank length" won't always find the right studies. But perhaps this little empirical experiment is closer to what you had in mind: bikeblather.blogspot.fr/2014/07/…
Jul
6
comment Analysis of Stages high-speed data
He may not have pedal angle but he does have a timestamp and thus elapsed time between peaks of the force or torque curve. Since the Stages only measures forces on the left crank, you could integrate over the cycle and do what Stages does: double it to get total power. If you were obsessive, you could do what has been proposed elsewhere: use the difference in trough-to-peak time to peak-to-trough time as an estimate of L/R balance to get a refined estimate of total power.
Jul
5
comment Analysis of Stages high-speed data
Here's my concern and hesitation: I'm puzzled because the patterns of those torque or force values aren't what I expected to see. Here is a plot of torque measured from special force-sensing pedals from the classic Kautz study on pedaling dynamics. anonymous.coward.free.fr/rbr/kautz.png In particular, single-sided torque (such as I would expect from the Stages) isn't as even as what I'm seeing in your data.
Jul
5
comment Analysis of Stages high-speed data
@dbr, here's a plot of the kgf and timestamp from your "full" data file: anonymous.coward.free.fr/wattage/stages/dbr2.png (and here's a plot of the first 128 kgf samples: anonymous.coward.free.fr/wattage/stages/dbr1.png)
Jul
5
comment Analysis of Stages high-speed data
Can you say a bit more about the full data set? Could it be that you did about 20 seconds worth of pedal strokes at roughly 60rpm, then coasted down, then did another 15 seconds or so at a slower cadence? Or am I completely off?