s5100e wrote:
I guess I am being pendantic, what you have is agreement, no one knows if any of the devices are accurate. So what you are conflating is accuracy which is a well defined term vs agreement. We agree that having a reading that is transferable is useful but there is no way that I am aware of to determine the accuracy of a bicycle power meter, and to date no one has educated me otherwise. This discussion has happened here before, to the same end. In general I think we agree, I am just a stickler for using the term accuracy when there is no internationally accepted standard to which a bicycle power meter can be calibrated against to certify it is "accurate". Just because 5 meters agree means they are consistent and agree in their output that is all, they all may be equally inaccurate.https://www.mcmaster.com/1788T74/
I know people who have bought these for use with calibrating power meters for accuracy (NIST certified). So, now you can't say you haven't been "educated otherwise" ;-)
That said, one can also get good results using weights that have been weighed on a calibrated scale.
You're welcome.
Oh yeah...and I'm one of those who see fairly large L/R discrepancies, depending on power output. MANY years ago I described here on ST how my L/R balance varies from as large 56/44 when at below threshold power, to basically 50/50 at threshold and above. Any effort below 40K TT power is going to show up to an 8% error due to that. Trying to evaluate an Ergomo power meter at the time for a ST review was an exercise in frustration (with the L only power measurement a big part of that).
http://bikeblather.blogspot.com/