So far the math is working out on a sample ride of some coliseum laps. I didn't like ignoring air speed versus ground, so added some vector math based on Weatherunderground from time of the ride.
Basically I paste in the GXP file and it spits out the graph. Guess at the CdA just like in GC to get the slope flat. Then add more runs to track changes.
FWIW, adding the vector addition for wind got the "CdA actual" away from being something super unrealistic to something MUCH closer to reality. Not reality, but instead of something stupid like 0.17 for clip-ons on a road bike........got it to 0.27. Much closer. That's not the point, the point is tracking changes. But, having a nicer value to work with helps a bit I think.
Will now play with this with multiple runs with obvious aero changes to do a stink test on the math and sheet.
Again, why???? A used laptop is like $250. This is just for fun.
Basically I paste in the GXP file and it spits out the graph. Guess at the CdA just like in GC to get the slope flat. Then add more runs to track changes.
FWIW, adding the vector addition for wind got the "CdA actual" away from being something super unrealistic to something MUCH closer to reality. Not reality, but instead of something stupid like 0.17 for clip-ons on a road bike........got it to 0.27. Much closer. That's not the point, the point is tracking changes. But, having a nicer value to work with helps a bit I think.
Will now play with this with multiple runs with obvious aero changes to do a stink test on the math and sheet.
Again, why???? A used laptop is like $250. This is just for fun.