CycleSync is a free app that keeps dozens of sound systems playing in lockstep using a shared GPS clock. It's brand-agnostic, so JBLs, Soundboks, and custom rigs all play together: no range limits, no breaking up when line of sight is lost, and no audible lag between speakers.
A group ride usually sounds like a dozen speakers fighting each other. CycleSync makes them one — every unit starting the same song on the same beat, so the ride moves like a rolling nightclub.
CycleSync doesn't care what you plug in. A JBL here, a Soundboks there, a custom high-power rig up front — they all lock to the same track and play as one. Bring whatever you've got.
Download CycleSync free on iOS or Android. On Android you're ready to ride; on iPhone, just connect the USB-C module.
Every speaker takes a slightly different amount of time to turn a play command into sound. A one-time calibration measures your setup's delay so the app can offset playback to cancel it.
By using GPS, every phone shares one precise clock to synchronize playback against.
Run an aux cable to your speaker, create or join a room with a short code, and hit play. Every speaker plays the same track, aligned to the millisecond.
CycleSync feeds your speaker or amplifier through an aux cable — never Bluetooth. Bluetooth adds unpredictable latency, and that lag between speakers is exactly what breaks a group's sync.
Android lets apps read the phone's own GPS timing directly, so CycleSync locks to GPS time with nothing but the app. Any modern Android phone works out of the box — no extra hardware to buy or carry.
iOS doesn't give apps direct access to the GPS receiver's raw timing, even with location permission enabled. That's the gap the handlebar module fills: a large, sky-facing antenna that feeds a rock-solid GPS clock over USB-C, so iPhones can stay locked to the same precise time — even in dense, obstructed urban conditions.
The CycleSync module mounts on your handlebars, feeds the app a precise GPS time reference, and gives you an audio output to your speaker.
The module is being designed now, with the first prototype expected September 2026. Android riders won't need any of this — the free app already syncs on its own.
Free on iOS and Android. Calibrate, create a room, queue the music, and call out to the whole ride — all from the phone already on your handlebars.
Turn a scattered string of speakers into one wall of sound. Everyone hears the same drop at the same moment — front of the ride to the back.
Queue the playlist before you roll out, hit play once, and call out turns, regroups and last songs over the music — heard on every phone at the same moment.
The app is in development and the CycleSync USB-C module is being designed now. If you lead rides, run a sound system, or just want to follow along, get in touch. We're actively looking for people interested in beta testing CycleSync.