01
Aerosensor
The drag measurement device. Reads air speed and yaw angle at the front of the bike and, combined with your power data, resolves your live CdA as you ride.
Aero Testing — Aerosensor — Canberra
Wind tunnel answers,
Wind tunnel answers,
on your road.
Field aerodynamic testing with the Aerosensor system. Real CdA numbers, measured while you ride — repeatability of ±1.5% out and back on the road, ±1% at an outdoor velodrome and ±0.5% at an indoor velodrome, the velodrome figures using the Aerodrome lap trigger.
The problem
Above 30km/h, aerodynamics is most of your race.
At speed, the overwhelming majority of the power you produce goes into pushing air out of the way. Everything else — rolling resistance, drivetrain losses, gravity on flat ground — is a rounding error by comparison.
Which means the single largest variable in your performance is one most riders have never measured. Position changes get made on feel. Equipment gets bought on marketing claims tested on a different rider in different conditions.
The answer
What CdA actually tells you.
CdA is your drag coefficient multiplied by your frontal area — a single figure describing how hard the air is fighting you.
The Aerosensor measures the power you're putting in, then subtracts the power going into acceleration, climbing and friction. What's left is aero power. From that, your CdA is calculated in real time.
Lower it, and you go faster for the same effort — permanently, in every event, without a single extra training hour.
±0.5%
CdA repeatability, indoor velodrome with the Aerodrome lap trigger. ±1% outdoor velodrome, ±1.5% out and back on the road.
±1.5%
Out and back on the road — the everyday number.
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Venues supported: road, velodrome or indoor trainer.
1
Variable changed at a time, so you know what bought the watts.
The system
The Aerosensor Complete System.
Three components working together — drag measurement, body position tracking, and precision lap timing.
02
Aerobody
A body position sensor giving a live measure of where you actually are on the bike — white at your reference, blue when you've dropped too low, red when you've come up too high.
03
Aerodrome
A wireless lap trigger that marks each run at exactly the same point, so runs compare cleanly rather than approximately.
The session
How a test day runs.
Step 01
Setup and baseline
Sensors fitted, system calibrated, and your baseline CdA established in your current position and equipment. Everything from here measures against that number.
Step 02
Run protocol
Repeated out-and-back runs at controlled effort, with the lap trigger marking each one identically. Repetition is what turns a reading into a result.
Step 03
Change one thing
Position, helmet, skinsuit, hand placement, bar width, wheels — tested one variable at a time so you know exactly which change bought which watts.
Step 04
Your report
You leave with your baseline, every variation tested, the CdA and watt saving for each, and a clear recommendation — plus the position reference to hold it.
What you need
Bring this with you.
- Your bike, set up as you race it. Race wheels, race position, the actual kit.
- A dual-sided power meter. ANT+, and reading accurately.
- A Garmin Edge head unit. Running a recent firmware version.
- A speed sensor. Magnet-based speed or speed/cadence.
- Every option you want tested. Helmets, suits, bottles, bar tape — if you want to know, bring it.
Who it's for
Worth testing if…
- You race time trials or triathlon. Where aerodynamics is close to the entire event and seconds decide it.
- You're about to spend real money. Testing before buying a disc wheel or an aero helmet routinely saves more than it costs.
- You've just been fitted. Aero testing validates the aero third of your bike fit with evidence rather than assumption.
- You're chasing a specific target. A course record, a qualifying time, a PB you've stalled short of.
- You coach riders. Defensible numbers to build a position and equipment plan around.
Measured, not modelled
Three ways to get a CdA. They answer different questions.
Wind tunnel, AI-CFD simulation and real-world field testing are not competitors — they measure different things. Knowing which one answers your question is most of the value.
Method 01
Wind tunnel
Genuine measurement in controlled air, and the reference standard. Accurate and repeatable, but expensive, usually interstate, time-limited and run in a synthetic environment. Most riders test once, if ever.
Method 02
AI-CFD simulation (AiRO)
A digital twin built from photographs, with computational fluid dynamics resolving the airflow. For rider position it tracks wind tunnel results closely and it is fast and affordable. Its limit is scope: it models the bike with assumed values rather than your actual frame, wheels and cockpit, so it answers "what shape should I hold" — not "what is my bike and kit actually costing me".
Method 03
Real-world field testing
The Aerosensor measures actual drag in real air, on your bike, in your kit, at real yaw angles, on the surface you race on — ±1.5% out and back on the road, tightening to ±1% and ±0.5% at an outdoor and indoor velodrome. It is the only method that measures the whole system rather than the rider alone.
Where simulation stops
Position is one variable. Your kit is a dozen more.
Simulation is very good at rider shape. What it cannot evaluate is everything that is not your body: skinsuit fabric and seam placement, socks, calf sleeves, overshoes, helmet choice on your head and shoulders, and how bottles interact with the frame — between-the-arms, behind-the-seat, or none at all.
Those are not marginal. Fabric alone can move CdA more than a significant position change, and a bottle that is fast on one bike is slow on another. None of it shows up in a model that assumes a generic bike and generic cloth.
Used together
Simulate to narrow it down. Measure to be sure.
The strongest workflow uses both. A fit establishes a position you can hold. Simulation then explores position variations cheaply and quickly, narrowing dozens of options to a shortlist worth testing.
Field testing takes that shortlist outdoors and confirms it against reality — your frame, your wheels, your suit, your bottle setup, and the interactions between them that no model sees.
- Simulation answers: which position should I try?
- Field testing answers: what does my whole setup actually cost me, and can I hold it?
Common questions
Aero testing, answered.
Where can I get aero testing done in Canberra?
At UpHill Performance in Wright, ACT. Field aerodynamic testing using the Aerosensor system is run on road, at a velodrome, or indoors on a trainer. It is the only real-world CdA testing in Canberra: drag measured outdoors in real air, on your bike and in your kit, rather than predicted by simulation.
What is CdA?
CdA is your drag coefficient multiplied by your frontal area — a single number describing how hard the air is fighting you. Lower your CdA and you go faster for exactly the same power output, in every event you ride.
How accurate is field aero testing compared to a wind tunnel?
Aerosensor publishes expected repeatability of ±1.5% for out-and-back road testing, ±1% at an outdoor velodrome and ±0.5% at an indoor velodrome, with the Aerodrome lap trigger required for both velodrome figures. Those hold while average wind speed stays below 25% of your road speed; testing is not recommended above 50%. On the wind tunnel question, Aerosensor report that when they tested discs of known drag in both a wind tunnel and an indoor velodrome, the system resolved changes equivalent to just 2 watts at 50km/h — which they describe as exceeding conventional wind tunnel precision. That is their figure, under indoor velodrome conditions. Out on the road the honest number is the ±1.5% above, and on a CdA of 0.250 that is about 0.004 — comfortably smaller than any change worth making.
Do I need a bike fit before aero testing?
Strongly recommended. Aero testing measures the position you turn up in, so testing an unfitted position optimises something you may not be able to hold or produce power in. A fit establishes comfort and efficiency first; aero testing then proves the aerodynamic half.
What equipment do I need to bring?
Your bike set up as you race it, a dual-sided ANT+ power meter reading accurately, a Garmin Edge head unit on recent firmware, and a magnet-based speed or speed/cadence sensor. Bring every helmet, skinsuit and component you want tested.
Who benefits most from aero testing?
Time triallists and triathletes first, since aerodynamics is close to the entire event. It also pays for anyone about to spend significant money on aero equipment — testing before you buy a disc wheel or aero helmet routinely saves more than the session costs.
Can aero testing be done indoors?
Yes. The system works on a static trainer as well as on road and velodrome, so testing is not dependent on weather or on booking a facility interstate.
What do I leave with?
Your baseline CdA, every variation tested, the CdA and watt saving for each change, a clear recommendation on what to keep, and the position reference you need to actually hold it.
How does AiRO compare to field aero testing?
They answer different questions. AiRO is an AI-CFD platform that builds a digital twin from photographs and resolves airflow around the rider. For position it tracks wind tunnel results closely, and it is fast and affordable. But it models the bike with assumed values rather than your actual frame and wheels, and it cannot evaluate skinsuit fabric, socks, calf sleeves, helmet fit or bottle placement. Field testing with the Aerosensor measures the whole system in real air. The two work best together: simulate to shortlist positions, then measure outdoors to confirm what your actual setup costs you.
Can aero testing measure my skinsuit, socks and calf sleeves?
Yes — and this is exactly where field testing earns its place. Fabric, seams, socks, calf sleeves, overshoes and helmet choice all change your drag, and none of them can be evaluated by a simulation that assumes generic clothing. Bring every option you want tested and each is measured one variable at a time.
Does bottle placement affect aerodynamics?
Significantly, and not predictably. Between-the-arms (BTA) and behind-the-seat (BTS) hydration can be faster or slower depending on your frame, position and yaw — a setup that gains watts on one bike loses them on another. It is measurable in the field and effectively invisible to a model that assumes a generic bike.
What is CdA measured in, and what is a good number?
CdA is expressed in square metres (m²) — drag coefficient multiplied by frontal area. Broadly, a well-positioned road rider sits around 0.30, a good time trial position nearer 0.22, and elite time triallists lower again. Absolute numbers matter less than your baseline and the change each modification produces.
Stop guessing at your biggest performance variable.
Aero testing in Canberra, run by an IBFI Level 2 bike fitter and physiotherapist — so the fast position is one your body can actually hold.