Follow the simple steps below to get estimates of CdA, Crr, or both
Upload your test file(s) (type .fit, .tcx or .srm with speed & power data)
You must be logged in to upload files
How should we identify laps?
Take intervals from the ride file (Intended for road laps of unknown length or multiple track laps)
metres is a lap (Intended for road or track laps of known length)
What sort of analysis do you want to do?
Solve lap-by-lap Crr given an estimated CdA for a
Time Trial Bike
(Low speed laps below 16kph / 10mph)
Solve lap-by-lap CdA given an estimated Crr on a
(High speed laps above 32kph / 20mph)
Solve one Crr & CdA (Requires a minimum of 10 laps with a speed differential of at least 1.6kph / 1mph per lap)
Local Air Density
Weight of Rider & Bike
You can calculate air density from a weather report.
WunderGround Historical Weather
Find the 'Hourly-Weather-History & Observations' for your locale.
Then, for the corresponding time of day...
Enter the Temperature:
Enter the Humidity:
Enter the Pressure:
Enter the elevation (altitude) of the locale:
Air Density Is:
Use this air density