CdA Calculation...

[tomkat4573]

Hey to all...the aero coeeficent obtained in the coast down procedure with the iBike Pro (rel 1.18), is that actual CdA or a number related to CdA? Thanks in advance!

[racerfern]

The aero coefficient divided by your wind offset calculation gives you your actual CdA. So they are related.

[tomkat4573]

Thanks very much for your reply! One other question..( I hope)..How do I convert the aero coeficent from the coast down to CdA? That is to say where do I get the other numbers needed to do the calc.?

[coachboyd]

When you do your out and back ride, the unit compares wind speed on the way out vs. on the way back, compared to wheel speed. This will give you a wind scaling number. This number is very important as it is what converts an aero number to a cda number. If you don't have the wind scaling number, you can't get a cda measurement.