As GoldenCheetah prepares for its upcoming release, I wanted to keep you all posted about the development of the virtual elevation module, Aerolab. Aerolab is not currently in Golden Cheetah, but I’m hoping it may eventually find its way there. There’s tons of work still to be done, but at least we now have a prototype that works.
To recap, Aerolab is a tool for estimating the coefficient of rolling resistance (Crr) and the aero coefficient of drag (CdA) of a bike/rider combination. It does this by reverse-engineering an elevation curve from power data using Newton’s Second Law. With the help of Justin Knotzke, I’ve put together some of Greg Steele’s ideas into a very preliminary tool.
Here’s a sneak peak of Aerolab. It’s not perfect, as a quick glance will tell you, but it’s starting to take shape. Below is a screenshot of an actual iBike ride. The green curve is the actual elevation profile, while the blue curve is the derived virtual elevation curve. Slider controls govern the values of Crr, CdA, rho, and total mass.
A first release will limit itself to only a manual solver mode, where the user tweaks all the parameters by hand to obtain the desired elevation curve. Future releases will include an “AUTOSOLVE” mode that uses VE’s Newton solver to automatically find the right parameter values of Crr and CdA.
That’s it for now. Stay tuned for lots more updates and maybe someday that this will see the light of day in Golden Cheetah!