Single or Dual Sided Power Meter
Posted: Tue Sep 11, 2018 1:59 am
I understand that to have an accurate CdA measurement it necessary to have a dual sided power meter - so to negate any right to left leg bias in power measurement.
However, I am not really that interested in obtaining an absolute accurate CdA measurements (within reasons). I just want to use my current TT setup at an outdoor velodrome as a referenced benchmark and investigate the change in CdA as i make adjustments. A bias in direct power measurement and CdA calculation should not impact this application.
So in that sense i am more reliant on precision of a single sided power meter. If a single sided power meter is in fact less precise (higher variance) then couldn't i just sample more data (ride for a longer time) so the measured average will reflect the true (biased) value.
Also, you have stated that the CdA measurement from the Aeropod is precise to three decimal places. What kind of changes in CdA should I expect from common practical changes made to a TT position or equipment? Will there be a significant jump in the first, second or third decimal place (1/10, 1/100 or 1/1000 CdA unit) in the CdA measurement? I had a look at some literature and it seems that a TT helmet improvement can result in an approximate increase of 0.03 CdA - which is well within the 0.000 precision specified for Aeropod measurement.
However, I am not really that interested in obtaining an absolute accurate CdA measurements (within reasons). I just want to use my current TT setup at an outdoor velodrome as a referenced benchmark and investigate the change in CdA as i make adjustments. A bias in direct power measurement and CdA calculation should not impact this application.
So in that sense i am more reliant on precision of a single sided power meter. If a single sided power meter is in fact less precise (higher variance) then couldn't i just sample more data (ride for a longer time) so the measured average will reflect the true (biased) value.
Also, you have stated that the CdA measurement from the Aeropod is precise to three decimal places. What kind of changes in CdA should I expect from common practical changes made to a TT position or equipment? Will there be a significant jump in the first, second or third decimal place (1/10, 1/100 or 1/1000 CdA unit) in the CdA measurement? I had a look at some literature and it seems that a TT helmet improvement can result in an approximate increase of 0.03 CdA - which is well within the 0.000 precision specified for Aeropod measurement.