Rev Log
An open source telemetry system for motorcycles. A camera records the ride and a GPS records the route. Rev Log records the machine itself: throttle, brakes, revs, lean, and how they change as a rider improves.
The motorcycle's flight recorder
Almost every data product in motorcycling is built for riders who are already fast. Lap timers assume you know what a good lap feels like. Dash loggers assume you can read one. Rev Log starts at the other end of the grid: a rider learning the craft, who wants proof they are getting better.
That changes what gets measured. A lap time tells you how fast you went once. Progression telemetry tracks smoother throttle, more confident braking, and more consistent lines, month over month. It is Strava logic applied to skill instead of speed.
And it ships open source first. The reference hardware, the firmware, and the ride-data format all go public before any product does. The format is designed to outlive the hardware, and the community around it is the point, not an audience for it.
This page is the project's public logbook, written before the first prototype on purpose. It gets updated as decisions are made, hardware gets built, and rides get logged. Last updated: July 2026.
Six decisions, written down
The reference points this project navigates by. If a feature or a shortcut fights one of these, the feature loses.
Open source before market
Success at this stage is measured in strangers: ten people who build one, the first pull request from someone we have never met, another tool that reads the format. Revenue questions wait their turn.
The data format is the crown jewel
A versioned, openly licensed spec for how a motorcycle is being ridden. Hardware revisions come and go; a good format outlives them all. The harness is the reference implementation, not the product.
Vehicle inputs are the point
Phones already do GPS and lean angle well enough. The reason hardware exists is the bike's nervous system: revs, throttle, brakes, wheel speed. That layer is core, never optional.
Analog first, CAN later
If it works on a carburetted 200cc single, it works on almost anything with a battery. RPM from the ignition coil, brake from the brake-light switch, speed from a hall sensor. CAN bus support is a future module, not a dependency.
Progression over performance
Feedback a novice can act on safely: smoothness, consistency, confidence. No machine-generated "brake later" advice. The numbers celebrate improvement; they do not push risk.
The rig never leads the riding
Training first, proper gear second, data third. The logger gets taped to a bike that is being ridden normally. If instrumenting the machine ever competes with learning to ride it, the data loses.
Boring parts, deliberate choices
Nothing exotic, on purpose. The bill of materials should be orderable by anyone, solderable on a kitchen table, and cheap enough to crash with.
- ESP32Reference logger and firmware target
- 9-axis IMULean, acceleration, braking forces
- GNSS receiverPosition, speed, heading
- Analog inputsRPM, throttle, brake, wheel speed
- microSDRides logged on-device, owned by the rider
- BLE · Wi-Fi · USB-CSync, configuration, flashing
- Ride format v0.1Versioned open spec, plain-text friendly
- Web visualiserRide playback and graphs in the browser
From bench to paddock
Phase zero runs on a four-month horizon. Everything after moves at the speed of evenings and weekends.
Groundwork
Rider training, first gear, and a project bike: a small single-cylinder machine that doubles as the development mule. On the bench, a first logger from off-the-shelf dev boards: ESP32, IMU, GPS, SD card.
Format v0.1 and a public repo
Freeze the first version of the ride-data format and publish everything: schema, firmware, build notes, and a web visualiser that turns a memory card full of numbers into a ride you can see.
Rides, documented in public
Real data logged from day one of the riding journey, published alongside the story. A telemetry project run by a beginner is the honest test of whether the output means anything.
Reference hardware
A custom PCB, the analog vehicle-input harness, and a vibration-tolerant, weather-sealed enclosure. Designed for hand assembly first, small batches second.
The ecosystem
Community builds, a CAN module for modern bikes, and analytics on top of the open format. Down the road, a motorcycle business in its own right: software, niche accessories, distribution, and one day a garage.
Riders, builders, and backers
Rev Log is not looking for customers yet; it is looking for people. Riders who want to own their data. Firmware and hardware folks who want a project worth soldering. Anyone who believes grassroots motorsport deserves open tools. If that is you, say hello.