CarBack pairs with your Garmin Varia rear-view radar and speaks "car back, 45 meters" through your iPhone speaker or Bluetooth headphones when vehicles approach from behind. No Garmin head unit required — just your phone in a jersey pocket.
How it works
Pair your Varia
Open CarBack, go to Settings, and pair your Garmin Varia radar over Bluetooth. One-time setup — it auto-reconnects on every ride.
Ride
Put your phone in your pocket or mount. CarBack works in the background — screen on or off.
Hear "car back"
When your Varia detects a vehicle approaching from behind, CarBack announces "car back, 45 meters" through your speaker or headphones. When the vehicle passes, you hear "all clear."
Why CarBack
Voice alerts with distance
Hear exactly how far back a vehicle is — "car back, 85 meters" — without taking your eyes off the road to check a screen.
Speaker or headphones
Works through your phone speaker, AirPods, Shokz, bone conduction headphones, or any Bluetooth audio device.
No head unit needed
Don't own a Garmin Edge? CarBack turns your iPhone into a voice-based radar display. Pair the Varia directly to your phone.
Varia battery level
See your Varia's battery percentage on screen so you never start a ride with a dead radar.
Works in your pocket
No screen interaction needed. CarBack runs in the background with audio alerts — your phone stays in your jersey pocket.
No account, no tracking
No sign-up, no servers, no data collection. CarBack connects directly to your Varia over Bluetooth. Nothing leaves your phone.
⚠️ Backup only — not a replacement
CarBack is a secondary alert layer. Always rely on your mirror, head-checks, and Garmin head unit first. Radar alerts may be missed, delayed, or fail silently. This feature is in a test phase and may change in future updates. Ride as if CarBack isn't there.
Compatible Varia models
CarBack works with Garmin Varia models that support Bluetooth Low Energy:
- Varia RTL515
- Varia RTL516
- Varia RVR315
- Varia eRTL615
- Varia RCT715
The older RTL510 and RTL500 use ANT+ only, which iOS doesn't support.
CarBack is from the makers of BikeTalk — proximity radio for cyclists.