I’m tackling a test concerning power measurements with a power2max.
As for
the sensor presentation, I suggest the excellent DCMaker
site for its complete illustration. There’s no point in trying to do the same POWER2MAX Test thing again, and it’s difficult
to do it as well!
What
interests me above all is the repeatability of the tool’s POWER2MAX Test measurements. The
latest development with the update for temperature variations seems
to be satisfactory. I took advantage of Rodolphe Lourd’s visit for the 3 Ballons
to have him try a powertap g3 wheel as a duplicate of his power2max and
play the guinea pig for an afternoon! Thanks to him!
Rodolphe
made a release by reviewing all the intensities telegram data from I2
to I6 for this test. Obviously it would be necessary to multiply the tests to be more
accurate. But since the DC Maker one is very comprehensive, I wanted to see if I
found a bit of the same conclusions. The loaned Powertap G3 wheel has already
served me several times in comparisons with my SRM, particularly in that
of the efficiency of bicycle chains . I am therefore quite confident in its accuracy.
The test output
On the
output we have underestimated differences of 1 to 2% between 200 and 320w compared
to the G3. This is quite consistent with DCMaker’s measurements. The
latter made a lot of readings around 200w but people will make assumptions about so it seems good. He
still noted a difference of 6% on max at 500w. This is also what I
note from 400w where the power2max seems to start to drift more. On all
the passages towards 400w of Rodolphe, there is a good 15 watts difference or 4%.
Summary
Around
500 to 600W we reach 6% but there may be an book your list explanation. Around 600W
Rodolphe only stayed there for a few seconds. On a zoom, we see that:
the powertap reaches the target value more quickly which could explain
a lower average calculation for the power2max over such short intervals.