Free FTP testing extension for Hammerhead Karoo cycling computers. No subscriptions, no accounts, works offline.

• Three FTP Test Protocols

  • Ramp Test: Progressive power increase until failure (~20 min)
  • 20-Minute Test: Classic FTP protocol with max sustained effort (~60 min)
  • 8-Minute Test: Two max effort intervals with recovery (~50 min)

• Real-time Data Fields

  • Current interval with progress bar (2x1 graphical)
  • Target power, test progress, power zone indicators
  • Deviation from target, elapsed time, average/max power
  • Live FTP prediction during ramp test

• In-Ride Alerts

  • Interval change notifications
  • Countdown warnings before transitions
  • Motivational messages
  • Test completion with calculated FTP

• Offline Operation

  • No internet or external accounts required
  • All data stored locally on device

1. Download the latest APK from releases
2. Transfer to your Karoo via USB or web dashboard
3. Install using file manager on device

Requirements:

• Android Studio or JDK 17+
• Gradle 8.x
• GitHub account (for Karoo SDK access)

The Karoo Extension SDK is hosted on GitHub Packages which requires authentication. Create a GitHub Personal Access Token with read:packages scope.

Add to ~/.gradle/gradle.properties (global) or project local.properties:

gpr.user=YOUR_GITHUB_USERNAME
gpr.key=YOUR_GITHUB_TOKEN

git clone https://github.com/yrkan/wattramp.git
cd wattramp
./gradlew assembleDebug

APK location: app/build/outputs/apk/debug/app-debug.apk

1. Setup: Open WattRamp app on Karoo, configure your current FTP and test preferences
2. Add Data Fields: In ride profile setup, add WattRamp data fields to your screen
3. Start Ride: Begin recording a ride
4. Run Test: Open WattRamp app during ride and select a test protocol
5. Follow Prompts: Watch data fields for target power and interval changes
6. View Results: After test completion, see calculated FTP and save to history

Coefficient can be adjusted in settings (conservative/standard/aggressive).

• Current FTP: Your baseline FTP for zone calculations
• Ramp Start Power: Initial wattage for ramp test (default: 100W)
• Ramp Step: Power increase per minute (default: 20W)
• Warmup/Cooldown Duration: Configurable warmup and cooldown periods
• Sound Alerts: Enable/disable audio notifications
• Screen Wake: Wake screen on important alerts
• Motivational Messages: Show encouragement during test
• Language: Multiple languages supported
• Theme: Orange or Blue color scheme

• Hammerhead Karoo 2 or Karoo 3
• Power meter (required for FTP testing)

WattRamp is designed with privacy in mind:

• All data stays on your device — no external servers, no cloud sync
• No accounts required — just install and use
• No analytics or tracking — we don't collect any usage data
• Open source — verify our privacy practices yourself

Read our full Privacy Policy.

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

• Issues: GitHub Issues
• Email: [email protected]
• Website: wattramp.com

MIT License — see LICENSE file for details.

• Built with Karoo Extension SDK
• FTP protocols based on established cycling science methodologies

Disclaimer: WattRamp is not affiliated with Hammerhead or SRAM. Karoo is a trademark of Hammerhead.