scott8888 wrote:
I can't get my head around the way they presented the data. This is not wind tunnel data so what they actually have is boat loads of files that contain values for speed and power at set time points. As they were using an notio connect they have also have a way to normalize all the data to set conditions creating an perfect power-speed relationship which is how they derive the CdA measurements. The logical way to present the data is therefore to provide plots of speed vs power which would appear like lines on an x-y graph where you look at the different systems by comparing lines. This would immediately allow you see the difference in watts between systems at a given speed or the difference in speed between systems for a given power. If you were desperate to show CdA you would superimpose idealized CDA lines on top of the comparison graph but that isn't very informative to 99.9999% of even the people who are looking at this sort of white paper. People want to know much faster will I be going hold 300 watts on this set-up vs this setup. For argument sake lets say Argon think people are too stupid to interpret a watts vs speed diagram. They still could have summarized the data better. They could have provided a table of all systems at 300 watts, 250 watts, 200 watts and 150 watts (with no required other reference) and simple provided the idealized speeds and then what this equates to over 90km. The beauty of using the Notio systems is that you are MEASURING watts and speed and so this is the data you showing (the whole CdA things is a technically fancy to present the watts vs speed in a comparable manner). As soon as they started trying to compare CdAs and then back extrapolate to watts and speed they lost me because it is as though they failed to understand the differences between a wind tunnel and a real world aero sensor.
So the first they do give. 18s over 90km all other things being equal, assuming a 0 degree yaw for the full course and holding 300w. Or 2:20 if you use the mystery wheels and change the position*.
For the second part, they would have needed to do a lot more testing, as they only got their version of the Stig to ride the 2km efforts at 300w.
In fairness, their approach was to do the testing using CFD. And then they validated that approach using the notio on road and in a velodrome. And what they saw was the the CFD seemed to basically match what they saw with the notio, and that was that the frame aero is pretty much (note pretty much) irrelevant nowadays, it's about the rider position, wheels and ability to store your bacon butty, teddy bear mascot and Park Tools bike stand. Which then of course makes writing a pseudo technical paper as an advertising pamphlet a bit tricky. Which is why this wasn't the first of the releases - they prefaced this with the storage, range of adjustment and ease of adjustment.
*note that if however you move out of the refined position then the entire thing goes to shit, and you are slower than someone on an old bike, not mystery wheels and your old position.