iBike iAero Generation III User manual

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Generation III Reference Manual
December 2010
Firmware 424+

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Setting up and Using the Gen III iAero
Your iBike Gen III Aero (“iAero”) shares many common elements with the Gen III iBike
Pro: mounting, calibrations, and software.
You will find detailed information regarding the many aspects of the iAero in other iBike
manuals (iBike operation, iBike Mount Installation, iBike software)
The iAero Reference Manual describes ONLY those features and benefits unique to
the iAero.

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Congratulations on the purchase of your Gen III iAeroTM Aero power meter!
Your new Generation III iBike®Aero power meter incorporates all the features of the
innovative iBike Pro power meter and adds important new features including aerodynamic
measurements and significantly improved power measurement performance under high
speed and rough roads conditions.
With the iBike Aero on your bike you’ll be able to learn much more about the amazing
influence of aerodynamics on cycling performance. And even more important, you’ll be
able to measure your personal aerodynamic characteristics with Snapshot CdA™
measurements, and determine the optimum combination of equipment, clothing, ride
position, along with power, to help you go your fastest.
Also, if you have a direct-force-power-meter (DFPM) on your bike, you’ll be able to see new
and exclusive Continuous CdA™ and Time Advantage™ measurements, either after your
ride with iBike software features, or even during your ride if you have an optional wireless
DFPM sensor that broadcasts power signals using ANT + Sport technology.
Without doubt the iBike Aero is the most sophisticated cycling computer ever designed and
with your iAero you’ll be able to taking your training efforts and cycling performance to the
next level.

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iBike®Aero power meter features
•Superior Reliability
oNo external screws for maximum moisture resistance
oImproved case design for superior performance in rain and better locking
•Precision Accuracy
oComparable to high-performance power meters
oNew microprocessor significantly improves on-the-bike accuracy
•Light-weight
o62 grams total weight
•Portable
oMoves easily and quickly to any of your bikes
oOn-the-bike profile storage simplifies portability
•Easy to Use
oInstalls and calibrates in minutes
oUses no special chain pickups, wheels, hubs or cranks
oImproved calibration procedures speed-up and verify calibrations
•Intelligent
oApproximately 13 hours of data storage, with readings stored once per second
oApproximately 65 hours with readings stored once every five seconds
oData storage of hill slope, wind speed, altitude, bike speed, and total
power for the entire ride
•Information-Rich
oInterval timer
oLap timer
oCumulative readings:
Calories
Kilojoules
Elevation gain
Trip distance
Trip time
Odometer
Total hours logged
oCurrent, average and maximum:
Power (watts)
Wind speed
Bike speed
Altitude
Hill slope
Temperature
oiAero: training Intervals (user-programmed sequences of time intervals and
training targets)
oiPro: pre-programmed interval workouts for weight loss, cardio, and strength o
oDate and time
oEnglish and metric units
oTrip data auto start/stop
oInnovative Sub Trip feature
oInstant-feedback bar graph
oHeart rate and cadence features built-in (requires optional accessories)
•Mac and PC Compatible
oFast, USB-based data transfer to your PC (XP and Vista) or Mac (Intel Mac)
oiBike software for data input, transfer, and ride analysis, both

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Mac and PC versions

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What’s in the Box
•Gen III iBike Aero power meter
•iBike wireless mount (stem or handlebar, depending on which model you
purchased)
•Wireless speed, cadence, and heart rate sensors
•Mounting hardware for wireless mount and sensor(s)
•iBike USB Adapter with cable
•CR2032 batteries
•iBike CD containing:
oRead Me First letter
oiBike Installation and Usage Manual
oiBike Software Reference Manual
oWireless Mount Instructions
oiBike software for Mac and PC:
!System Requirements:
•Windows XP or above, 128 MB RAM
•Intel Mac with Mac OS X 10.4 (Tiger) or above, 128 MB RAM
oiBike Consumer Warranty
NOTE: IN ORDER TO RECEIVE FREE SOFTWARE AND FIRMWARE UPDATES PLEASE
BE SURE TO REGISTER YOUR IBIKE AT:
http://www.ibikesports.com/register/registration.aspx
NOTE: CONSULT YOUR iBIKE SOFTWARE MANUAL TO OBTAIN INSTRUCTIONS FOR
DOWNLOADING THE SERIAL NUMBER STORED IN YOUR i’BIKES MEMORY.

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SETTING UP AND USING THE IAERO
NOTE: FOR BEST RESULTS WE STRONGLY
RECOMMENDED THAT YOU FAMILIARIZE
YOURSELF WITH THE “iBIKE OPERATING
INSTRUCTIONS”, “iBIKE MOUNT
INSTRUCTIONS”, AND “IBIKE SOFTWARE
INSTRUCTIONS” BEFORE READING THIS
MANUAL

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IMPORTANT: IBIKE AERO CALIBRATIONS
The iAero is a precision measurement instrument that, when calibrated properly, provides
very useful and highly accurate measurements of power and aerodynamic data.
The key is this: accurate iAero measurements are a result of proper setup and calibration!
Please read the iBike Instructions to familiarize yourself with basic tilt, wind offset, and
coast down calibration procedures. Make sure you understand them.
Having understood these procedures please remember this: YOUR IAERO REQUIRES
CAREFUL CALIBRATION. FOR GOOD RESULTS WITH YOUR IAERO YOU MUST DO TILT,
WIND OFFSET, COAST DOWN, AND CALIBRATION RIDES PROPERLY!
Also, for highest accuracy results, prior to each ride you should acclimate your iAero to
riding temperature and perform the simple wind offset calibration.
The last two paragraphs are not meant to be scary; in fact, iAero calibrations are very
simple to perform, take only a small amount of time to complete, and need to be done only
once. But if they’re done improperly, or partially, or not at all (!), you’ll get less accurate
results from your iAero. So, DO YOUR CALIBRATIONS COMPLETELY AND PROPERLY!
TIPS
1) Be careful and take your time. If you’re doing a tilt calibration, mark the places
where you’ll turn the bike. After completing the tilt calibration, check your result. If
you’re doing coast-downs, remember MORE IS BETTER. Five coast-downs are
better than four, and 10 are better than 5.
NOTE: IF YOU’RE USING YOUR iAERO WITH AN ANT+SPORT WIRELESS DFPM POWER
SENSOR, THE CALIBRATION PROCEDURES ARE DIFFERENT. SEE A LATER
SECTION IN THIS MANUAL FOR DETAILS.
2) VERY IMPORTANT: before doing any calibrations make sure your iAero has adjusted
to the outdoor temperature. In particular, accurate wind speed measurement is
critical to best results, so BEFORE you start calibrations, ride around with your bike
for 10 minutes to let your iAero adjust to outdoor conditions.
3) Be certain that you perform the Wind Offset calibration before beginning your coast-
downs and calibration ride.
4) For coast downs pick a road that is level to uphill and is relatively free of wind gusts
caused by cars, trucks, or weather. REMEMBER: you’ll do these coast-downs only
once, so do it right: if it’s windy, or traffic is heavy, wait for a better day!
5) If you’re using a DFPM (direct-force power meter) as your reference for calibrations,
make sure you’ve checked the calibration of your DFPM. If your DFPM calibration is
incorrect then ALL the data from your iAero will be wrong, too!
6) When you’ve completed your calibration rides use the “Profiles/Download Coast-
Downs & Calibration Ride” command data to analyze your results. And, VERY
IMPORTANT, after you’ve done the analysis click the “Accept Profile and send to
iBike” command to UPLOAD your analyzed results to your iAero. If you forget this
step then ALL YOUR HARD WORK WILL BE MEANINGLESS!
These six tips will make the difference between superb results and exasperating problems.

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Follow these tips carefully and you’ll get your iAero going quickly and accurately!

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USING THE iAERO FOR AERODYNAMICS
MEASUREMENT
The iAero provides accurate and useful aerodynamic data as well as accurate and useful
power data.
As is the case with any measurement instrument, knowing how the iAero works will help
you understand when it is providing you maximum-accuracy data, and when won’t be as
accurate.
The governing principle is this: the force applied to the pedals is equaled by the forces
opposing the bike’s forward motion (Newton’s Third Law).
The iAero measures opposing forces: opposing gravity (hills), opposing acceleration
(inertia), opposing wind, and opposing friction. These opposing forces slow down the bike
and the cyclist applies forces at the pedal that precisely equal the opposing forces,
moment-by moment.
For aerodynamic measurements, applied and opposing forces must both be known. Why?
When applied and opposing forces are known simultaneously,then drag coefficients can be
determined in a straightforward manner.
The iAero measures two different but related kinds of aerodynamic drag coefficients, based
on two different ways of measuring applied forces:
1) Snapshot CdA™. Whenever you’re coasting the applied force is known exactly (it’s
zero!). The rider holds his position still and the iAero measures opposing forces
while coasting (say, while coasting down a hill). The aerodynamic drag coefficient is
measured as a “point-in-time” snapshot. Snapshot CdA is very similar to what is
measured in a wind tunnel.
2) Continuous CdA™. In this situation both an iAero AND a wireless direct-force power
meter (DFPM) are on the bike, providing applied-force information to the iAero. The
DFPM provides continuous, accurate applied force data to the iAero. The iAero
compares DFPM data to opposing force data and computes drag coefficients
continuously, in real time. The restrictions of Snapshot CdA do not apply: you can
be pedaling, changing ride position, even changing clothing. Continuous CdA
provides constant updates on your CdA, and provides the basis for an amazing new
measurement called Time Advantage™.
Needless to say, in either measurement scenario lots of fancy physics and computations
are going on inside the iAero.
IMPORTANT
Aerodynamic measurements are tricky to make, especially outdoors. There are situations
when the iAero will work very well, and others where it will have trouble. Here they are:
iAero drag coefficient and Time Advantage measurements are best when:
1) iAero calibrations are performed properly (!)
2) Tilt calibration is correct (should not be an issue unless mount is loose or you’ve
adjusted your handlebars)

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3) Wind offset is performed before the ride, after the iAero is acclimated to outdoor
temperature
4) You’re doing a solo ride (not in a pack)
5) The pavement quality is the same as that used in the calibration ride
6) Cross-winds are small
7) Temperature is reasonably constant during ride
8) Bike is working properly (i.e. brakes aren’t rubbing on the wheels, tires are inflated
properly)
9) (DFPM ONLY) your DFPM is calibrated properly and working properly
iAero drag coefficient and Time Advantage measurements aren’t as good when:
1) You’re drafting
2) when you’ve performed the setup calibrations improperly
3) you do not perform wind offset properly before the ride
4) road conditions are significantly different from your calibration ride (e.g you
calibrated on asphalt but you’re riding on a sandy beach)
5) ride temperatures change by 20F or more during the ride
6) Your bike’s condition has changed significantly (e.g tire pressure is low)
SUMMARY: YOUR IAERO WORKS BEST WHEN 1) IT IS SET UP AND CALIBRATED
PROPERLY; 2) YOU’VE CHECKED TILT AND PERFORMED A WIND OFFSET CALIBRATION
PRIOR TO YOUR RIDE; 3) YOU’RE RIDING SOLO; 4) ROAD CONDITIONS ARE SIMILAR TO
THOSE OF YOUR CALIBRATION RIDE

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UNDERSTANDING HOW TO USE YOUR IAERO
FOR CdA MEASUREMENTS
The ability to measure aerodynamic drag while riding is a revolutionary new
feature made possible by the iAero. Please take a few moments to read this
section so you can learn how the iAero works. Understanding how the iAero
works will help you tremendously as you use your iAero to improve your cycling
performance.
When you perform the initial coast-downs and calibration ride, the iAero and the iBike
software together determine your “baseline” aerodynamic and frictional drag coefficients.
These coefficients characterize your “normal” riding position and “normal” road/bike
condition. These baseline aerodynamic and frictional drag coefficients are stored in the
iAero.
What’s new in the iAero is the ability to explore changes in your ride position, equipment,
and clothing, and to see their effect on your baseline aerodynamic drag coefficient.
Suppose your baseline aerodynamic drag coefficient is 0.28 (this number is determined in
your calibration ride and is displayed in each of your ride files): by how much will your CdA
decrease if you go into a tuck? What penalty (higher CdA) do you pay if you put on a
jacket?
These are the kinds of questions any iAero can answer with ease.
The iAero provides two kinds of CdA measurements: Snapshot CdA™, and Continuous
CdA™. Snapshot CdA measurements are available from any iAero, but Continuous CdA
measurements require the use of a direct force power meter (DFPM).
The following sections will explain each kind of CdA measurement in detail.

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HOW TO MEASURE SNAPSHOT CDA WITH THE
IAERO
What is Snapshot CdA Measurement?
Imagine that you’re riding your bike but that you are coasting and your body isn’t moving.
Your feet are stationary, your riding position isn’t changing, and your clothes are the same.
It’s as if someone took a snapshot of you and your bike.
In this fixed position your bike and body present an unchanging (that is, fixed in time)
barrier to wind and friction.
Snapshot CdA is the aerodynamic coefficient measured by the iAero whenever you’re not
pedaling and you’re holding your body fixed. This is the kind of static CdA measurement
performed in wind tunnels.
Snapshot CdA measurement can be performed by the iAero whenever you coast for 10
seconds. While coasting you hold the same position and after 10 seconds the iAero reports
your Snapshot CdA number. If, say, you perform your Snapshot CdA measurements on a
hill, then you can coast down the hill, experimenting with ride positions, equipment, etc.
and the iAero will report your Snapshot CdA measurement on your iAero screen. Since the
hill is the same you can ride back to the top of the hill, change ride positions, coast down
the hill, and see how your CdA changes.
How does Snapshot CdA measurement work? Whenever you stop pedaling the iAero knows
the following: applied force (zero, because you’re not pedaling), opposing hill slope force
(the iAero measures this), iAero-measured opposing acceleration force, and iAero
calculated opposing frictional force (determined from the frictional drag coefficient
measured during the calibration ride). So, the only remaining opposing force is from the
wind. Since the iAero measures wind speed, it can calculate WHAT aerodynamic drag
coefficient is required to make applied force = opposing force.
Now that you know the theory, here’s the practical how-to:
Measuring Snapshot CdA Drag Coefficients
1) Find a quiet place where the wind isn’t howling, trucks and cars aren’t screaming by
you, and the road surface is like the one where you did your calibration ride.
2) Ideally, this spot is a downhill, so that you can let nature help you coast (gravity
pulls you down and speeds you up), and nature slows you down (opposing wind). If
you don’t have a downhill available that’s OK: just find a place where you can go
fast, then coast for 10 seconds or more.
NOTE: DURING THE CdA COAST DOWN YOU CANNOT APPLY BRAKES, TURN SHARP
CORNERS, OR BE BUFFETED BY WIND GUSTS FROM PASSING VEHICLES. IF ANY OF
THESE HAPPEN YOUR MEASUREMENTS WILL BE INACCURATE.
3) Select the power window on your iAero screen
4) Go to your starting point, speed up to at least 20 mph, then stop pedaling. It’s ok if
downhills make you continue to speed up more; the iAero will figure out the forces
properly.
5) Hold the same riding position while coasting. Do NOT move your pedals while

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coasting: if your cadence is not zero, the iAero will not perform CdA calculations.
6) About 10 seconds after you’ve stopped pedaling, you will see your Snapshot CdA
coefficient appear in the bottom window of your power screen. Read it as follows:
0_28 = 0.28 (i.e. Snapshot CdA = 0.28)
iAero CdA measurements are read out to two significant digits.
Now that you know how to measure Snapshot CdA, you can have fun:
For each riding position, equipment set-up, etc. do several measurements (more data is
BETTER). Write down Snapshot CdA results after each coast-down. You can average them
later on.
You can compare your measured, Snapshot CdA numbers to the baseline Snapshot CdA
number stored in your iAero. When your Snapshot CdA numbers are LOWER than your
baseline CdA number then you’re more streamlined against the wind (compared to your
usual ride position) and it will be easier to go faster.
When your aerodynamic coefficient goes UP, compared to your baseline CdA, it will take
more effort to move against the wind.

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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.

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With the wireless DFPM and iAero working together at every point of the ride the iAero
knows: applied force (from the DFPM), opposing gravitational force (iAero), opposing
acceleration force (iAero), and opposing frictional force (iAero, based on baseline frictional
drag coefficient). The only remaining opposing force is due to the wind and the iAero can
determine, in real time, the CdA value required to make the above equation balance.
The iAero uses the same physics and mathematics to determine CdA; what’s different is
that CdA data is displayed continuously on the iAero screen.
SUMMARY: CONTINUOUS CDA REQUIRES THE IAERO AND A COMPATIBLE WIRELESS
DFPM TO BE MOUNTED ON YOUR BIKE.

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USING THE iAERO WITH AN ANT+SPORT
WIRELESS DFPM POWER SENSORS
HOW TO CONNECT THE IAERO WITH YOUR WIRELESS ANT+SPORT SENSORS
1) Install your wireless DFPM on your bike according to directions provided by the
manufacturer.
2) Install your iAero wireless mount and sensors on your bike.
3) Attach your iAero to your wireless mount.
4) Spin the crank to wake up the speed sensor, cadence sensor, and DFPM.
5) Attach the HR strap to your chest. This wakes-up the HR strap.
6) Spin the crank of your DFPM backwards several revolutions. This activates your
DFPM.
7) Enter Setup and use the down arrow to find the “Scan No” screen.
8) Click the center button; “No” will flash. Click the up arrow so that “Yes” flashes.
9) Finally, press the center button of your iAero. Your iBike will scan for your wireless
sensors and, after a few moments, you’ll see “SPD FOUND”, “CAD FOUND”, “Pin
FOUND” (power in found). If you’re using an HR strap you’ll also see “HRT FOUND”.
Your iAero is now receiving speed and HR signals from your iAero sensors, and cadende
and power data from your DFPM.
HOW TO ZERO-OFFSET CALIBRATE YOUR WIRELESS DFPM
1) Pair your wireless DFPM according to the steps above.
2) Go to Setup/PCAL (power calibrate).
3) Use the up arrow to find PCAL/START
4) Press the center button. After a few seconds you’ll see the message PCAL/Done.
Your wireless DFPM is now calibrated.
NOTE: FOR DETAILED INSTRUCTIONS REGARDING THE USE OF YOUR WIRELESS DFPM,
CONSULT THE DFPM OWNER’S MANUAL THAT WAS INCLUDED WITH YOUR DFPM
NOTE: WHEN USING A WIRELESS DFPM WITH THE IAERO, THE POWER INFORMATION
DISPLAYED ON THE IAERO SCREEN IS MEASURED BY THE DFPM.

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CALIBRATING YOUR IAERO AND WIRELESS
DFPM TOGETHER FOR CONTINUOUS CDA
MEASUREMENT
The calibration procedure for the iAero/WIRELESS DFPM combination is COMPLETELY
DIFFERENT FROM ANY PREVIOUS IBIKE CALIBRATION PROCEDURE:
a. Tilt calibration is the same, but
b. NO COAST DOWNS ARE REQUIRED
c. A single calibration ride, 4 miles long, IS REQUIRED
d. The 4-mile ride is analyzed in iBike software.
e. Baseline (normal) aerodynamic and frictional drag coefficients are
determined by the iAero/DFPM data
Here is the calibration procedure:
1) Set up your iAero and DFPM on the bike and pair them (page 15)
2) Perform a tilt calibration. Be careful and take your time. Mark the places where
you’ll turn the bike.
3) VERY IMPORTANT: before starting your calibration ride make sure your iAero has
adjusted to the outdoor temperature. Proper wind speed measurement is critical to
best results, so BEFORE you start calibrations, ride around with your bike for 10
minutes to let your iAero adjust to outdoor conditions.
4) Be certain that you perform the Wind Offset calibration carefully before beginning
your calibration ride.
5) Make sure the DFPM has had its zero-offset calibration completed. If your DFPM
calibration is incorrect then ALL the data from your iAero will be wrong, too!
6) Once your iAero and DFPM are ready, do a four mile calibration ride (two miles out,
two miles back).
NOTE: WHEN USING THE IAERO AND THE DFPM TOGETHER, THE POWER DATA
DISPLAYED ON YOUR IAERO SCREEN WILL BE THAT MEASURED BY THE DFPM
7) When you’ve completed your calibration ride use the “Profiles/Download Coast-
Downs & Calibration Ride” command data to analyze your results. The iBike
software will compute aerodynamic and frictional drag coefficients based on the
DFPM and iAero data captured during the calibration ride.
8) And, VERY IMPORTANT, after you’ve done the analysis click the “Accept Profile and
send to iAero” command to UPLOAD your analyzed results to your iAero. If you
forget this step then ALL YOUR HARD WORK WILL BE MEANINGLESS!
Your iAero and DFPM are now ready to measure power, Continuous CdA, Time
Advantage, and all other iAero measurements.
Note that iAero Continuous CdA measurements are read out to two significant digits.

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TIME ADVANTAGE
Time Advantage™ is another feature exclusive to the iAero/DFPM combination.
What is Time Advantage?
When you ride a bike, most of the time you’re riding in your “normal” position.
DEFINITION: YOUR “NORMAL RIDING POSITION” IS THE POSITION YOU USED WHEN
PERFORMING THE CALIBRATION RIDE WITH YOUR DFPM.
As long as you stay in your normal riding position, the relative amount of time it takes to
complete your training ride is unaffected by your riding position; that is, your “normal”
riding position gives a “normal” training time.
Now, suppose you’re on a ride and you have deviated from your normal riding position for
a portion of your ride, say, going into a tuck. Did going into a tuck save you time
compared to staying in your normal riding position? Clearly, the answer is “yes”, but how
much time did you save?
Here’s another situation: you attacked a hill and stood up to get more power. You know
that “standing up” is less aerodynamically efficient and costs you some time. How much
extra time did it take to climb the hill due to aerodynamic inefficiencies?
A final situation: you’ve perfected your “normal” ride position using the iAero. During a
long ride, however, you get tired and your ride position becomes a bit sloppy. How much
longer did it take you to complete your ride because your ride position became worse?
Time Advantage answers all these questions, and more.
DEFINITION: AT ANY POINT OF YOUR RIDE, “TIME ADVANTAGE” IS THE CUMULATIVE
AMOUNT OF TIME YOU HAVE GAINED (OR LOST) UP TO THAT POINT, DUE TO DEVIATIONS
FROM YOUR NORMAL RIDE POSITION.
Time advantage is measured in seconds. Suppose you look at your iAero at mile 6.2 of
your ride and Time Advantage reads a positive 30. Then, up to that point of your ride you
have gained 30 seconds of time, relative to your “normal” riding time, as a consequence of
moment-to-moment improvements of your normal riding position. If, instead, your Time
Advantage reads -15 then you’ve lost fifteen seconds compared to staying in your normal
riding position.
How are Continuous CdA and Time Advantage related?
If your current value CdA is higher than your baseline CdA then you are relatively less
aerodynamically efficient compared to your normal riding position and, for the same
amount of applied force, you won’t go as fast. Conversely, if your current CdA is lower
than your normal value then you are MORE aerodynamic and you’ll go faster compared to
your normal riding position.
The iAero compares your Continuous CdA to your baseline CdA, moment-by-moment.
Using the comparative CdA values between your baseline CdA and your Continuous CdA,