Testing of helmets - success reproducing results across sessions
Posted: Thu Sep 03, 2020 3:03 am
I'd like to share my recent experiences with the Aeropod and testing of CdA out in the field.
A little background: I bought my Aeropod thru the kickstarter campaign, and initially I was disappointed with the reliability of the tests I did. I wrote about my findings on this messageboard, one thing lead to another, and I ended up being beta-tester of firmware. I've been involved in that for about a year now. I've done many test sessions and I have shared a lot of files with John Hamann from Velocomp.
While not perfect, I will say that with the current firmware (7.15) it is possible to do some solid testing. Testing outdoors is never going to be easy or fault-proof, there will always be the random, hard to explain outlier lap that one just has to discard from a session. I have found though, that there is a fair amount of tolerance towards wind conditions, if the test course allows for consistent riding across test laps.
Some numbers from two, recent sessions to illustrate this.
I am comparing two helmets (Giant Rivet TT vs Met Drone). I'm riding on my tt-bike, but with training wheels and in training kit, so the absolute CdA-numbers aren't impressive. However, I'm able to reproduce a difference in CdA of about 0.002 between these two helmets across two sessions on different days, in different conditions. This is something like 3 watts at race pace - enough to matter, but a small difference. I think that is pretty good for outdoors testing.
Session 1, 2020-06-27:
Session 2, 2020-08-28:
As you all probably know, the most recent version of the Garmin ConnectIQ data field records CdA, wind speed and slope in the .fit-file, making it possible to analyse results in WKO5.
I have attached the .fit-file from the last session, if anyone is interested in looking at the numbers themselves.
/Rolf
A little background: I bought my Aeropod thru the kickstarter campaign, and initially I was disappointed with the reliability of the tests I did. I wrote about my findings on this messageboard, one thing lead to another, and I ended up being beta-tester of firmware. I've been involved in that for about a year now. I've done many test sessions and I have shared a lot of files with John Hamann from Velocomp.
While not perfect, I will say that with the current firmware (7.15) it is possible to do some solid testing. Testing outdoors is never going to be easy or fault-proof, there will always be the random, hard to explain outlier lap that one just has to discard from a session. I have found though, that there is a fair amount of tolerance towards wind conditions, if the test course allows for consistent riding across test laps.
Some numbers from two, recent sessions to illustrate this.
I am comparing two helmets (Giant Rivet TT vs Met Drone). I'm riding on my tt-bike, but with training wheels and in training kit, so the absolute CdA-numbers aren't impressive. However, I'm able to reproduce a difference in CdA of about 0.002 between these two helmets across two sessions on different days, in different conditions. This is something like 3 watts at race pace - enough to matter, but a small difference. I think that is pretty good for outdoors testing.
Session 1, 2020-06-27:
Session 2, 2020-08-28:
As you all probably know, the most recent version of the Garmin ConnectIQ data field records CdA, wind speed and slope in the .fit-file, making it possible to analyse results in WKO5.
I have attached the .fit-file from the last session, if anyone is interested in looking at the numbers themselves.
/Rolf