Lean angle

Measure motorcycle lean angle.
With your smartphone.

No extra sensor, no cloud: MotionRecord computes your lean angle live while you ride — and captures the motion sensors already built into your phone at up to 100 Hz.

MotionRecord is a free app for iOS and Android that computes motorcycle lean angle while you ride, from GPS course and speed (φ = arctan(v · ω / g)), and shows it live. In parallel it records gyroscope, accelerometer and magnetometer as raw data at up to 100 Hz — for detailed analysis later, on your computer or in Kurvenfokus.

Live computation instead of after-the-fact analysis

Lean angle relies on the same physics as GPX-based analysis — but MotionRecord computes it while you ride and captures the raw sensor data at the same time:

	GPX analysis afterwards	MotionRecord
Lean angle	after the ride, from the file	live while you ride
Computation	from corner radius and speed	from GPS course and speed (φ = arctan(v·ω/g))
Raw sensor data	not included	gyroscope, accelerometer, magnetometer up to 100 Hz
G-forces	not included	longitudinal, lateral and vertical
Export	depends on the app	CSV, GPX, JSON — up to 37 fields per sample

Start recording in 3 steps

1

Install the app

Get MotionRecord for free — Android on Google Play, iOS as a TestFlight beta. No account required.
2

Mount your phone rigidly

Firmly mounted beats clearly visible: vibration is the enemy of every measurement. Orientation doesn't matter — MotionRecord automatically transforms all axes into the vehicle coordinate system.
3

Start recording and ride

Start the recording, stow the phone, ride. The app runs in the background — even while you navigate with Calimoto or Komoot. After the ride: review lean angle, G-forces and elevation, or export to Kurvenfokus.

Lean angle measurement — FAQ

How does MotionRecord compute lean angle?

Continuously, from GPS course and speed: φ = arctan(v · ω / g), where ω is how fast your heading changes. On Android the gyroscope additionally smooths the live value (complementary filter). The angle is clamped (±45° on iOS, ±55° on Android) and shown while you ride. Independently of that, the app records your motion sensors at up to 100 Hz.

Do I need an external lean angle sensor?

No. The GPS receiver in your smartphone is enough for lean angle. The sensors recorded alongside it — gyroscope, accelerometer, magnetometer — are already built into your phone as well.

Does the phone need a specific mounting orientation?

Not for lean angle — that comes from GPS data. For the recorded sensor data, MotionRecord transforms all axes into the vehicle coordinate system automatically. What matters most is a rigid, low-vibration mount.

Does lean angle work without GPS reception?

No. If GPS drops out — in a tunnel or dense forest — no lean angle values are produced for that stretch. Sensor recording continues, so the ride itself stays fully documented.

What happens to my data after recording?

Your sensor and tour data stay on your device — no account, no server, no forced cloud. Export as CSV, GPX or JSON, or hand it straight to Kurvenfokus for tour analysis.

Try it for free

MotionRecord is free — Android on Google Play, iOS as a TestFlight beta.

And after the ride?

To analyze entire tours — corner by corner, with map and statistics — there is Kurvenfokus. MotionRecord records, Kurvenfokus analyzes:

kurvenfokus.de – analyze motorcycle tours ↗

Measure motorcycle lean angle.With your smartphone.