Download rides from a Cycplus M2 (and other XOSS-family) GPS bike computer straight to your
Android phone over Bluetooth LE, write them into Health Connect, and export the raw .fit
files anywhere you like — without the vendor cloud, without an account, without the XOSS app.
| Rides | Bulk selection | Settings |
|---|---|---|
 |
 |
 |
The stock workflow sends every ride through the vendor's cloud, and the Google side of it is
disappearing too: the Google Fit APIs are shut down at the end of 2026 and the Fit app is being
replaced by Google Health, with Health Connect as the on-device store everything now talks to.
This app writes directly into Health Connect, so your rides land where Google Health and anything
else that reads that store can pick them up — and the .fit files stay yours.
Strava is the exception worth knowing about: its Health Connect link only goes one way. Strava
writes activities into Health Connect and reads weight back out, but it never reads activities
from it, so rides will not reach Strava this way. Getting them there means uploading the .fit
yourself — the share button hands you the file — because as of June 2026 Strava's API needs a paid
Strava subscription on its Standard tier, which is where an app like this one lands.
- Bluetooth LE sync — finds the bike computer, downloads only new rides (228 KB in ~13 s)
- Health Connect import — cycling session with GPS route, heart rate, cadence, speed, distance, elevation gain; pauses are written as segments so moving time stays correct
- No duplicates — de-duplicated by
clientRecordId, re-running a sync is safe - Raw
.fitexport — share one ride or many at once, with readable file names like2026-07-24_10-30_40.99km_cycplus-m2.fit - Calories the M2 never records — estimated from heart rate (Keytel et al., 2005), with a
speed-based MET fallback, and written as
TotalCaloriesBurnedRecord - Smart scale support — reads weight straight off a Bluetooth scale's advertisement and files it in Health Connect; the fresh weight feeds the calorie estimate
- Verify — reads the rides back out of Health Connect and reports what is missing, plus which other apps wrote records for the same days
- Sync on launch — opening the app finds the bike computer and pulls new rides in ~3 s
- Update check — asks GitHub Releases for a newer version, then downloads and installs it in place: the APK is fetched in-app, checked against the published sha256, and handed to the system installer, so all you see is Android's own "update this app?" dialog
- Ride in detail — tap a ride for its route on an OpenStreetMap basemap plus elevation, speed, heart-rate and cadence charts you can scrub with a finger
- 3D fly-through — fly the track from a bird's-eye chase camera, with the map draped on the ground in perspective; drag to orbit, pinch to zoom, double-tap to recentre. No API key and no account, and the basemap switches off if you want the ride to stay fully offline
- Fully scriptable over ADB — every action runs headless, no tapping required
- Material 3 Expressive UI with dynamic colour, English and Russian localisation
- Device card — model, firmware, battery, free memory read straight off the device
Grab the APK from Releases and install it, or build from source:
git clone https://github.com/andrewkomkov/cycplus-m2-sync.git
cd cycplus-m2-sync/android
./gradlew :app:assembleDebug
adb install -r app/build/outputs/apk/debug/app-debug.apkRequirements: Android 13 or newer with Health Connect (built into Android 14+).
Debug builds install as dev.komkov.m2sync.debug, so they sit next to a release build instead of
replacing it. Substitute that package name in the ADB commands below when you build from source.
Permissions can be granted from the app (lock icon), or entirely from a terminal:
for p in BLUETOOTH_SCAN BLUETOOTH_CONNECT POST_NOTIFICATIONS; do
adb shell pm grant dev.komkov.m2sync android.permission.$p
done
for p in WRITE_EXERCISE WRITE_EXERCISE_ROUTE WRITE_HEART_RATE WRITE_DISTANCE \
WRITE_SPEED WRITE_ELEVATION_GAINED WRITE_TOTAL_CALORIES_BURNED WRITE_WEIGHT \
READ_EXERCISE READ_HEART_RATE READ_DISTANCE READ_SPEED READ_WEIGHT; do
adb shell pm grant dev.komkov.m2sync android.permission.health.$p
done$S.PERMS prints the exact list the current build expects, so it stays honest when the set changes.
S="adb shell am start-foreground-service -n dev.komkov.m2sync/.SyncService -a dev.komkov.m2sync"
$S.SCAN # look for the bike computer
$S.SYNC # download new rides and import them
$S.SYNC -e name M2_XXXX # target a specific device
$S.INFO # firmware, battery, free memory
$S.IMPORT # import already downloaded files only
$S.IMPORT -e force 1 # re-import everything (after changing import logic)
$S.STATUS # what is stored locally
$S.VERIFY # read back from Health Connect and compare
$S.WEIGH # wait for a scale reading and store the weight
$S.PERMS # permission strings Health Connect expects
adb logcat -s M2SYNC # follow the workDownloaded files live in /storage/emulated/0/Android/data/dev.komkov.m2sync/files/fit:
adb pull /storage/emulated/0/Android/data/dev.komkov.m2sync/files/fit ./ridesVerified on Cycplus M2, firmware V1.4.0.
The same Nordic UART + YMODEM protocol is used across the XOSS family, so these are expected to
work with the --name prefix adjusted: XOSS G / G+ Gen1 / G2+ / Gen3 / NAV / Sprint,
Cycplus M1 / M3, CooSpo BC102 / BC107 / BC200. Newer models (NAV, G2+) list rides in
workouts.json instead of filelist.txt — not yet handled. Reports welcome.
| Health Connect record | Source in the .fit |
|---|---|
ExerciseSessionRecord (biking) + ExerciseRoute |
session + 1 Hz GPS track |
ExerciseSegment (biking / pause) |
gaps in the recording |
HeartRateRecord |
heart_rate per record |
CyclingPedalingCadenceRecord |
cadence |
SpeedRecord, DistanceRecord |
enhanced_speed, session total |
ElevationGainedRecord |
total_ascent |
TotalCaloriesBurnedRecord |
estimated — see below |
WeightRecord |
a Bluetooth scale, not the bike computer |
The M2 records none: total_calories is empty in both session and lap. So the app estimates
them itself — from heart rate with the Keytel et al. (2005) equation, which needs exactly what the
.fit already has per second, and from speed via MET (Compendium of Physical Activities) where
heart rate is missing. Both models give gross expenditure over moving time, which is the semantics
TotalCaloriesBurnedRecord asks for. A ride that does carry total_calories is taken as is.
The estimate needs weight, year of birth and sex. Weight comes from the latest WeightRecord in
Health Connect — the ⚖ button fills it from a Bluetooth scale. Year of birth and sex are read from
the Health Connect medical record (FHIR Patient) when it has them, and asked for once in
⋮ → Profile for calories otherwise. Change any of it and the rides recalculate on the spot.
Weight is read from the standard Weight Scale advertisement (0x181D) — no pairing, no GATT
connection, the app just listens. Verified on Mi Smart Scale 2. Body composition is not
available over the air: impedance travels in the 13-byte 0x181B packet the scale does not
broadcast, and Mi Fit computes body fat on the phone.
The device speaks YMODEM over the Nordic UART Service. Full write-up with commands, quirks and per-model differences: docs/PROTOCOL.md.
Python CLI for pulling rides without a phone, and for probing an unknown model:
pip install -r tools/requirements.txt
python tools/m2_cli.py scan # BLE devices nearby
python tools/m2_cli.py info # model, firmware, battery, free space
python tools/m2_cli.py sync # download new .fit into ./fit
python tools/m2_cli.py services # full GATT map — useful for new devices
python tools/fit_summary.py # what is inside the downloaded filesRides never leave the phone: no analytics, no account, no upload. The only network request the app
can make is an optional version check against api.github.com/repos/…/releases/latest, which sends
nothing but a User-Agent and can be switched off in the ⋮ menu. Weight, year of birth and sex are
used for the calorie estimate only and never leave the device — the profile lives in the app's own
preferences, the weight in Health Connect.
- ekspla/xoss_sync — the working Python implementation of the protocol that this project started from
- Kaiserdragon2/CycSync — an earlier Android attempt aimed at the Cycplus M2
- Garmin FIT SDK — FIT decoding
Not affiliated with Cycplus, XOSS, Garmin or Google.
MIT — see LICENSE.