iBike iAero Generation III, Справочное руководство

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Copyright Velocomp LLP 2008-2010
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HOW TO MEASURE CONTINUOUS CDA WITH
THE IAERO
Continuous CdA Measurement
Continuous CdA measurements allow your body to be in motion at all times:
(e.g. pedaling,
changing ride position, changing clothing); you don’t have be motionless. Continuous CdA
measurements are made once each second and are recorded in your ride file .
Continuous CdA is like a movie of your aerodynamic behavior at every point of your ride, in
contrast to Snapshot CdA, which is a point-in-time snapshot of your static aerodynamic
characteristics.
What are the benefits of Continuous CdA measurement? Several:
1) No rider stays in the same position all the time. Continuous CdA tells you when and
by how much you are deviating from your normal ride position.
2) With Continuous CdA, you can optimize the combination of power output AND ride
position simultaneously. Perhaps your most streamlined riding position isn’t the
position from which you generate the most power. Continuous CdA measurements,
along with the iAero’s power measurements, will help you get your best combination
of ride position and power.
3) In a long ride your riding position may worsen due to fatigue. Continuous CdA will
help you see how disciplined your ride position remains for the entire ride.
4) Continuous CdA enables another amazing measurement: Time Advantage™. Time
Advantage will be discussed in a separate section.
In short, Continuous CdA takes power training to a much higher level and opens serious
training to exciting new possibilities.
How Does Continuous CdA Measurement work and what does it require?
We’ve already learned that Snapshot CdA works by determining the aerodynamic drag
coefficient that solves the equation
Applied forces = opposing forces
For Snapshot CdA, the rider is coasting and applied force = 0.
Of course, most of the time the cyclist is pedaling (!), applying force directly to the pedals.
The iAero does not know the magnitude of the applied force and CdA can no longer be
determined unless…
…unless you have a direct force power meter (DFPM) installed on your bike that transmits
its applied force power data to the iAero.
As of the time of this writing (November 2008) the iAero can receive DFPM power signals
sent by the Quarq CinQo, SRM Wireless, and PowerTap ANT+. All three DFPMs use
ANT+Sport communication technology, allowing the iAero to receive DFPM signals. It is
anticipated that more DFPM manufacturers will adopt ANT+Sport for wireless; when they
do, the iAero will be able to receive power signals from these other manufacturers as well.