Hi Stu,
Do you feel your position was almost identical with each helmet?
Was your speed (air speed preferably) very similar for each test run?
If it both the above are yes then I see no reason to change the calibration factor which is simply making the big (and often incorrect) assumption that your out and back runs had exactly the same wind conditions (opposite direction) and therefore net to 0.

How do the results look with a single CF of 1.365?

I cannot see the data in that image

Another way to sanity check it would be to use the Virtual elevation model. Notio used to populate the headwind column (I think they left that there).

Yes, pick a factor (or an average) and stick with that for this type of tests. Calibration factor could get us into a 4 page conversation

Thanks, how do you do virtual elevation in Notio GC? It seems to be all locked out. I don't think standard GC has the capability to look at wind data and adjust VE? If it does I'd love to know how to do it.

Thanks for the reply and advice, I found I was able to add the standard aerolab tab into GC Notio and look at the curves. I think they look good and would appreciate some feedback on them. Last weekend I tested two different skin suits and tested ABBA.

The test course I use is a circuit round and industrial estate, with very smooth tarmac, consistent around the loop. There are a couple of large speed humps. The laps are ~1.45km each and I do 5 laps and just use the middle 3.

So nagging queries I have are:
1) Do the plots look reliable?
2) I use my Garmin autolap feature , which gives me the lap brakes. Is this accurate enough?
3) The GC Notio computes my CdA for my selected middle laps and the value is usually just a little bit off what I estimate my CdA for each lap, does anyone know how it calculates it? I think it is looking exactly at the elevation at the start and end of the selection but am not sure.
4) Air density for a selection - is there a quick way to extract the average measured air density from the Notio file for this?

Here are example plots from the Notio analysis and then the same data in standard Aerolab.Any feedback appreciated.




Cheers,
Stuart

Just to build on Marc's points. On a lap circuit like this, it sometimes helps to put "Constant altitude" setting on in your second image in GC - then what all your focus is making sure the blue virtual elevation profiles from lap to lap are consistent (e.g. peaks, nadirs and unique parts of the profile of the lap "line up") rather than trying to match the actual and virtual elevation. When you do this, i'm sure you might even spot the speed bumps in the lap profile.

I agree with Marc that in the second setting the CdA looks set a bit low given your virtual elevation is drifting up from lap to lap.

Crr of 0.005 might potentially be high if the tarmac is very smooth and fast. Might want to try do runs at many different speeds to see if you can dial the estimate in, but overall it can be tough to tease out CRR vs CdA effects.

Also, i think if you create a strava segment, and mark it as a favourite within Garmin, then it shows up automatically as a lap in Golden Cheetah without having to create laps during the ride (or post ride in GC) - this is a helpful feature for aero testing. I can't remember the exact procedure but sure you can google it.

raises more questions than answers, for me... Off the top of my head, but will probably think of more later...

1) How does an algorithm know a vehicle has past, versus say a "natural" wind gust? Personally I'd rather it just computes the calculation and leave it up to me to recall/record non-natural interventions on my runs and then decide what to do with the data from that run...
2) How many repeats during a session of a set up do you do and what are the errors in reproducibility?
3) In a similar vain, what error in reproducibility for the calibration factor do you observe, more so with your outdoor testing, and what wind conditions have you been successfully able to test in to produce reproducible cal fac data (not CdA data...)?
4) Was the device positioned in the same spatial coordinates relative to the non-adjusted parts of the bike for the two aerobar set-ups? Were the cal facs different and if so was that accounted for in the presented data?

As an N.B.... Even last year the aerosensor software allowed one to see the data immediately after the runs on the garmin connect IQ app, and since then both the firmware and software aspects have been updated further...

Thanks