Your Virtual Athlete simulates your activity for you. This provides you with the most accurate environmental data prior to your activity. When analysing a past activity your Virtual Athletes settings will be used to mimick you on the road.

Where to find these setting

Select Sport

You can select your Virtual Athlete’s to be either a Cyclist or Runner.

Power in Watts

This is the power you expect to average in each scenario of your route, uphill, flat, downhill. Uphills and downhills are triggered at greater than +2% and less than -2% gradient.

The average male rider will expect to average 100-150 watts on a moderately paced ride of 2-3 hours. Average female riders will ride at 80-125 watts on a moderately paced ride of the same time.

If you know neither your CdA nor your power use the Suggest Power Settings button.

Aerodynamic Drag in CdA

Drag in CdA is the aerodynamic performance of the rider. An average rider on a road bike hoods will be between 0.32-0.38. A time trialist can be as low as 0.17. Premium members, enter the CdA Estimation from past rides here.

Methods for estimating your CdA:

The following are ways to estimate your CdA to enter into your forecasts.

1. Pick a number, eyeball from averages…
   Time Trial Position: 0.17 – 0.25
   Road bike (race): 0.24-0.3
   Road bike (summer): 0.27-0.32
   Road bike (winter): 0.3-0.36
2. myWindsock.com CdA Calculation
   Premium members can enter the estimated CdA from previous rides. To get the best estimate check out the advice here. Find out more about Premium features.
3. Estimate from average power data
   If you have a power meter choose a route and course you have completed in the past. This should be a relatively flat route and the start and finish should be roughly the same point. Ideally loops or out and back courses. Now enter the average power and your weight from a previous effort. Adjust the CdA until the Ground Speed is roughly what you would expect for your ride.

Weight

Enter the weight of you and any other equipment. A good ballpark figure for cycling is your weight plus 10kg to get you close. If you are using the Premium CdA estimator it is best to weigh yourself holding bike for the most accurate estimate.

Rolling Resistance

This is the efficiency of your tyres on the road. Most road bike tyres are around 0.005. Light weight time trial tyres are close to 0.004. For a good guide on rolling resistance for various tyres check out http://www.bicyclerollingresistance.com/

Please keep in mind that the tyre is only one part of the rolling resistance equation. Road surface is highly variable. Think how difficult it is to ride on a field compared to a road. For average roads it is sensible to have a number of between 0.004 – 0.005 as your rolling resistance coefficient. Very rough roads can be as high as 0.008!

Drivetrain Loss

A percentage of the Watts that are lost in the drivetrain. If you have measured your watts using a hub based power meter this will be 0%. Most drivetrains will result in a loss of around 3% of your power.