SVC.01 / AERO
DisciplineTT · Tri · Road · MTB MethodReal-world · CIRRUS Accuracy± 2 W on drag Session~ 2 hours · 10 configs From£420

Save watts you didn't know you were losing.

Cycling is dominated by aerodynamics — across every discipline. Using the Streamlines CIRRUS system we measure your drag in the real world, on roads you actually ride, then iterate kit and position until the numbers say you're fast.

John Hale racing the Aethelred Ultra
01 — Process

Four steps. One morning on the road.

N = 04 · v.2026
STEP01
SENSOR FIT · 15 MIN

Fit

ALTOSTRATUS, FORMA, TEMPO and the NIMBUS data logger mounted to your bike. Power meter required.

STEP02
COURSE · 600 – 1000 m

Set up

Straight, low-traffic course with under 1% gradient — a quiet local road or cycle path near you.

STEP03
RIDE · 8 – 10 RUNS

Ride

Repeat the course while we swap positions, helmets, suits and wheels. Wind & yaw logged live.

STEP04
PORTAL · SAME DAY

Result

CdA per run on the CIRRUS portal. Written report and a 60-min review call to lock in changes.

In partnership with
Streamlines Aero

We test using CIRRUS — the real-world aerodynamic drag measurement system from Streamlines Aero. It measures drag to within 2 watts on everyday roads, not a wind tunnel, so we can iterate your position and kit on the courses you actually race.

About the CIRRUS system →
“Testing with Streamlines makes it possible to test and train on the spot and give instantaneous feedback on aero gains.”Mathieu Heijboer · Head of Performance, Visma–Lease a Bike
ALTOSTRATUSWind sensor
Four-port probe · wind speed to 0.2%, direction to 0.1°, altitude & air density.
FORMABody position
Three infrared lasers track head & chest position — ~75% of a rider's drag.
TEMPOSpeed sensor
Microsecond wheel-speed timing — 10× more precise than standard sensors.
NIMBUSData logger
Captures every sensor on-bike, then syncs to the cloud for analysis.
CIRRUS PortalResults
Automatic calibration & calculation — clear CdA you can read run-to-run.
02 — The measurement

Measured, not estimated.

Every change is tested on the road and measured directly — so the numbers in your report are your own, not a rule of thumb.

Measurement accuracy
± 2W
CIRRUS drag accuracy in real-world wind & road conditions.
·
Configs / session
10+
Positions, helmets, suits and wheels tested back-to-back in ~ 2 h.
+
03 — Equipment

What you actually book.

SELECT A PACKAGE
PKG.01BENCHMARK

Single Session

One 2-hour CIRRUS session on a local course. Baseline your current position and kit.

Test runs6 – 8
Portal access30 days
From£420
PKG.02STANDARD

Position Programme

Two sessions, one to baseline and one to validate. Most popular. Full position iteration.

Test runs16 – 20
Review call60 min
From£750
PKG.03RACE-READY

Full Kit Audit

Three sessions sweeping position, helmets, suits and wheels — race-day setup, locked.

Test runs30+
Kit SKUsup to 8
From£1,250
04 — FAQ

Questions we hear, most often.

Q.01Do I need a TT bike?+
No. We test road bikes, gravel bikes and MTBs as often as TT setups — the method is identical, only the position changes.
Q.02Do I need a power meter?+
Yes. CIRRUS needs a calibrated power meter on your bike — it pairs that with our sensors (ALTOSTRATUS, FORMA, TEMPO) to compute drag.
Q.03What if it's windy?+
Fine in almost any conditions safe to ride in. The ALTOSTRATUS sensor measures wind speed to 0.2% and direction to 0.1° so we compensate run-by-run.
Q.04Where do we actually test?+
A quiet local road or cycle path with under 1% gradient and around 600–1000 m of clear straight. We'll scout one near the studio or your base.
Q.05Can I bring my own helmet / suit / wheels?+
Absolutely — and we encourage it. The Race-Ready package will sweep your kit against current benchmarks in a single session.
Q.06When do I get the report?+
Run-by-run CdA is in the CIRRUS portal the same day. A written report plus a 60-min review call follow within 72 hours.

Ready to find your watts? Book a scan and we'll handle the rest.