App that helps build positive bike maintenance behaviours, for rides quick, big
About this app
We have all experienced those rides where something mechanical happens that really was preventable. As the authors, even though we take a certain pride in our own efforts in maintaining smooth running MTBs, and a disdain for our riding buddies who never give a passing thought until something goes 'CRUNCH!' in a ride-ending manner, there are still innumerate situations where something that should have been checked, or usually never needs checked after proper installation, has not been.
'Where is that vibration coming from?', 'why is the rear end creaking?', 'What is that terrible knocking?' are so often result of something relatively simple being overlooked or forgotten. Recent favourites have been disc rotor bolts backing out, rear thru axles not done up properly, and headsets improperly tensioned.
So, to prevent mechanical disasters happening on your rides, use this app to build better, new, habits and ensure your rides are (mechanically) glorious.
The app can connect ot Strava and update mileages/distances as well as last ride dates.
This app uses INTERNET and ACCESS_NETWORK_STATE permissions to download template activities from a github repository at https://github.com/janexner/JKBikeTemplateActivities, and to retrieve data from 3rd-party integrations, currently with Intervals.icu only. No internet access beyond that.
Licensed under EUPL-1.2, by Jan Exner.
What's New in v4.2.1
Imported from the F-Droid repository index.
- - [Simple & Pro] fixed loading of Template Activities in local language on first start
- - [Simple & Pro] more UI smoothing
- - [Simple & Pro] bumped libraries
- - [Simple & Pro] updated translations (Spanish), thanks @andresbott
Version history
Jun 21, 2026 · 5.2 MB · Android API 29–37 · code 27
Imported from the F-Droid repository index.
- - [Simple & Pro] fixed loading of Template Activities in local language on first start
- - [Simple & Pro] more UI smoothing
- - [Simple & Pro] bumped libraries
- - [Simple & Pro] updated translations (Spanish), thanks @andresbott
SHA-256 780302301840e3071c3291316b0c317671432f7155ea660bf2ca40877c128b7d
May 28, 2026 · 5.1 MB · Android API 29–37 · code 26
Imported from the F-Droid repository index.
- - [Simple & Pro] fixed navigation on big screens (tablets and such)
- - [Simple & Pro] made UI more modern (using Material 3 Expressive)
- - [Simple & Pro] fixed display of completed Activities
- - [Simple & Pro] fixed navigation flow for Activities
SHA-256 733eda703094a14f72b5d0ffa940cfc9871ce1df845932044cb9b81f6e50925a
May 23, 2026 · 4.9 MB · Android API 29–37 · code 25
Imported from the F-Droid repository index.
- - [Simple & Pro] added Spanish translation (primera tradución al castellano por: José M. «correoxm at disroot . org» Por favor, informa de los errores que encuentres o de mejoras a realizar. Gracias.)
- - [Simple & Pro] fixed a lot of hard-coded text across every part of the apps
- - [Simple & Pro] improved content of export screen when there is no data
- - [Simple & Pro] improved UI in dark mode with dynamic colours, and added preference to disable dynamic colours
- - [Simple & Pro] changed splash scr
SHA-256 6838f254bef3d8d0381ff46675bb05674824a37db1d105eeddff91851f3b74b9
Will it run on your device?
74%
- Targets newer Android builds, so legacy devices may be excluded.
- Multiple CPU architectures are covered.
- Aligned with the latest Android target SDK expectations.
Installation Guide
Open Settings on your Android device
Go to Security → Unknown sources (or Install unknown apps)
Enable "Allow from this source" for your browser or file manager
Open the downloaded APK file from your Downloads folder
Tap "Install" and wait for installation to complete
Launch the app from your home screen
Make sure to re-enable Unknown Sources restrictions after installation for security.
How to install this safely
How to verify the file you downloaded
Before you install anything, confirm the file is the one described here. On a computer, run shasum -a 256 your-download.apk (macOS or Linux) or certutil -hashfile your-download.apk SHA256 (Windows), then compare the output character-for-character with the SHA-256 on this page. If a single character differs, the file is not the build we recorded — delete it.
What the signing certificate proves
Every Android app is signed with a private key that only its developer holds. The fingerprint on this page is a hash of the matching public certificate, and it proves continuity rather than identity: it tells you a build came from whoever signed the earlier ones. Android enforces this at install time — if a package claiming to be com.exner.tools.jkbikemechanicaldisasterprevention.light is signed with a different key, the system will refuse to install it over your existing copy. A fingerprint that changes between releases is worth pausing on, because a repackaged app that has been modified by someone else cannot keep the original signature.
How to roll back to an earlier version
If the current release misbehaves, 4.2.0 is the last build before it. Android will not install an older version code over a newer one, so you must uninstall J-K Bike - Mechanical Disaster Prevention first — which clears its local data unless you have a backup. Reinstall the older APK only if its signing fingerprint matches the build you already trust, and check the API range: an older release may target an Android version your device has moved past.
Why we list sources instead of hosting everything
The official store channel is almost always the right choice: it updates automatically and carries the publisher's own distribution guarantees. A direct APK is useful when a device has no store access, when a rollout has not reached your region, or when you need a specific version — and only when the publisher has authorized that copy. APKBrowse does not list pirated, cracked, or unauthorized rebuilds of J-K Bike - Mechanical Disaster Prevention, and a listing is removed when the evidence for it stops holding up.
Get J-K Bike - Mechanical Disaster Prevention
Every source we list for com.exner.tools.jkbikemechanicaldisasterprevention.light is legality-reviewed. Pirated or cracked builds are never offered.
Other sources
F-Droid listing
officialF-Droid builds this app from source and signs it. This is its official listing, with older builds and full release notes.
Source code
verified publisherThe upstream repository this build is compiled from.
We check legality and signature continuity, but device behaviour still varies. Install at your own discretion.
App Information
Security Verification
We record provenance; we do not run malware scans. Verify the hash yourself before installing.
SHA-256 Hash
780302301840e3071c3291316b0c317671432f7155ea660bf2ca40877c128b7d
Signing certificate
07a89b9b74e8d980673671912166ace204c2f73523cd631b933cb4f77ac4a2cf
Permissions Required
Previous Versions
The signing certificate fingerprint for this release is on record, so a build that does not match it did not come from this publisher.
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