Our RaceBox Mini S delivers 25 Hz GPS and a 6-DOF IMU — but no barometer and no magnetometer. Your smartphone has exactly those. MotionRecord records the missing sensors at 100 Hz. Together that makes a telemetry setup that beats professional data loggers on data density — for a fraction of the cost.
Why two devices instead of one?
Our RaceBox Mini S is impressive: 25 Hz multi-GNSS, accelerometer and gyroscope with a 1 kHz internal sample rate. It measures lean angle and G-forces. But it lacks two sensors:
- Barometer: altitude only via GPS → ±10 m inaccuracy. On a mountain pass with 1,800 m of elevation gain, the altitude profile is jagged and useless.
- Magnetometer: heading only via GPS course angle. At a standstill or low speed: no heading available.
Your smartphone has both. MotionRecord uses them.
What MotionRecord delivers
MotionRecord is a sensor recorder for iOS and Android. The app records all smartphone sensors simultaneously — at up to 100 Hz. That's 360,000 data points per hour.
| Sensor | Rate | What it provides |
|---|---|---|
| Accelerometer | 100 Hz | G-forces under braking, acceleration, in corners |
| Gyroscope | 100 Hz | Rotation rate around all 3 axes → lean angle |
| Barometer | 10–25 Hz | Altitude to ±1 m — 10× better than GPS |
| Magnetometer | 100 Hz | Compass heading, even at a standstill |
| Rotation Vector | 100 Hz | Exact 3D orientation of the smartphone |
| GPS | 1 Hz | Position and speed (smartphone GPS) |
MotionRecord runs in the background — you can use Calimoto, Kurviger or another navigation app at the same time. Sensor recording needs minimal CPU and battery.
The combination: filling the gaps
When you run RaceBox and MotionRecord at the same time, their strengths complement each other:
| Sensor | RaceBox Mini S | MotionRecord | Combination |
|---|---|---|---|
| GPS position | 25 Hz | 1 Hz | 25 Hz (RaceBox) |
| Accelerometer | 1 kHz internal | 100 Hz | Doubled — cross-validation possible |
| Gyroscope | 1 kHz internal | 100 Hz | Doubled — cross-validation possible |
| Barometer | — | 10–25 Hz | Smartphone fills the gap |
| Magnetometer | — | 100 Hz | Smartphone fills the gap |
The result: 25 Hz precision GPS + 100 Hz IMU + barometer + magnetometer. That's more data density than an AiM Solo 2 DL (10 Hz GPS, ~€800–1,200) — for ~€260 of hardware plus two free apps.
Compared to professional systems
| System | GPS | IMU | Baro | Price |
|---|---|---|---|---|
| Smartphone alone | 1 Hz | 100 Hz | ✓ | €0 |
| RaceBox Mini S alone | 25 Hz | 1 kHz | — | ~€260 |
| RaceBox + MotionRecord | 25 Hz | 100 Hz + 1 kHz | ✓ | ~€260 |
| AiM Solo 2 DL | 10 Hz | ✓ | — | ~€1,200 |
| 2D data recording | 20 Hz | ✓ | ✓ | ~€3,000+ |
The RaceBox + MotionRecord combination is the sweet spot: more GPS resolution than the AiM Solo 2, plus a barometer and magnetometer — for a fifth of the price.
The workflow
- Before the ride: attach our RaceBox Mini S magnetically to the tank. Start MotionRecord on the smartphone (background recording). Put the smartphone in the bar mount or tank-bag pocket.
- During the ride: both record independently and simultaneously. The RaceBox stores internally (Mini S), MotionRecord stores on the smartphone. No Bluetooth needed while riding.
- After the ride: export the VBO file from the RaceBox → import into Kurvenfokus (iOS). The MotionRecord recording with barometer altitude profile and sensor data is available separately.
- Analysis in Kurvenfokus: corners, lean angle, tour score, heatmap — now with 25× more GPS resolution and a precise altitude profile.
Practical tips
- RaceBox position: magnetically on the tank, as central as possible. Not on the handlebar — it vibrates more and distorts IMU data.
- Smartphone position: firmly mounted, not loose in a bag. The more stable the mount, the better the gyroscope data.
- Battery: MotionRecord in the background draws little power. Still: a USB-C charging cable on the bar is a must for rides over 3 hours.
- Export: always choose VBO, not GPX. GPX contains no lean angle and no G-forces — half of the RaceBox data is lost.
Outlook: Bluetooth integration
Right now RaceBox and MotionRecord run independently. The data is only merged in Kurvenfokus after the ride. But RaceBox provides an open Bluetooth protocol documentation — and that opens up an exciting possibility:
Real-time sensor fusion. MotionRecord could receive the RaceBox data via Bluetooth and synchronize it with the smartphone sensors — 25 Hz GPS + 100 Hz IMU + barometer + magnetometer in a single, time-synchronized data stream. That would be telemetry quality otherwise only possible with hard-wired professional systems.
That's the plan. We have the protocol documentation. The implementation follows.
Conclusion: start free, upgrade when you're ready
You don't need a RaceBox to get started. MotionRecord alone delivers 360,000 data points per hour — more than enough for tour analysis. Kurvenfokus analyses the data for free.
When you want more — more precise corner analysis, track-day lap times, professional line comparisons — the RaceBox Mini S is the logical upgrade. Together with MotionRecord you get a setup that doesn't need to hide from professional systems.
MotionRecord and Kurvenfokus are developed by MVXLabs. RaceBox is an independent product — our Mini S was bought and paid for by us. Technical specs: racebox.pro (as of June 2026).