Trek CarBack Radar Rear Light

How many light modes does Trek CarBack Radar Rear Light have?

Trek CarBack features four modes – Day Flash, Day Steady, Night Flash and Night Steady modes.

How do you turn on/off your Trek CarBack?

Pressing and holding the power button for one second powers CarBack on and off.

Can the Battery Status be checked without turning the CarBack on?

Yes, a quick press of the power button will temporarily activate the power status LEDs showing the battery status.

How long does the battery last for Trek CarBack?

The stated battery life is 7 hours. Battery life can vary depending on the activity of the Radar system and number of rear-approaching vehicles identified by CarBack while riding. The actual battery life will often exceed the stated battery life.

How long does it take to fully charge Trek CarBack?

CarBack will generally take 3.5–4 hours for a full charge with the included USB-C charging cable. The charging time is dependent on the power source and can vary.

What type of charger does Trek CarBack work with?

USB-C, a USB-C charger cable is included.

What is the IPX rating for CarBack?

CarBack has an IPX7 waterproof rating.

From what distance does CarBack detect rear-approaching vehicles?

When installed correctly and under ideal conditions, CarBack can detect rear approaching vehicles from up to 240m. ANT+ protocol for radar does have a limit of 196m, so a Bluetooth connection with a phone running the Trek Accessories App is required to realize detection distances beyond 196m. It is also worth noting that some third party apps plug-ins for GPS head units have limits to the reported distances that they will show, even if actual detection ranges are longer.

How do I factory reset my Trek CarBack?

To reset the CarBack to your factory settings, you hold the power button for 15 seconds. CarBack will flash once at 8 seconds and again at 15 seconds, indicating that the factory default settings have been restored.

What can Trek CarBack detect behind me?

The Trek CarBack can detect vehicles, motorcycles and cyclists depending on their size, location and travel direction relative to the rider.

What cycling computers are compatible with Trek CarBack?

Most GPS cycling computers are compatible. CarBack uses universal ANT + protocol to communicate to GPS cycling computers and watches. See the full list of ANT+ compatible devices here

ANT+ compatible devices

Is Trek CarBack Blendr-compatible?

Yes, Trek CarBack works with the Trek Saddle Accessory Blendr mount as well as several bike model-specific integrated Blendr light mounts.

Does CarBack work with the Blendr Fendr?

No, CarBack and the Blendr Fendr are not compatible.

Can Trek CarBack be mounted on a helmet Blendr mount?

We do not recommend helmet-mounting Trek CarBack. Trek CarBack works best when securely mounted to a fixed part of the bike, ensuring the most consistent operation and detection of rear-approaching vehicles.

What is the visible distance that CarBack can be seen from?

Trek CarBack is a proven Daytime Running Light and can be seen from up to 2 km during the day.

Are there any firmware versions for major GPS units that are not compatible with CarBack?

We always recommend ensuring that your GPS unit is running the latest firmware version for the best experience. There were some now outdated firmware versions that inhibit certain aspect of Radar and CarBack functionality. Check with your GPS Head unit manufacturer for the latest firmware for best experience.

Can you charge CarBack while using it?

Yes, you can plug CarBack Radar into an external battery bank while in use to extend the battery life. It will turn off when you plug it in, but you can then turn it back on again for use while charging.

Why are all of the light modes stated as having the same battery life for CarBack?

Radar is the largest driver of battery use, far greater than the flash of the light. We officially state runtime as 7 hours in all modes from the 2,000 mAh battery, but again it is radar-dependent. Seven hours would be worse-case, with Radar constantly working and being the main driver of the battery. When no cars are being picked up by the radar, the radar goes into battery-saving mode and provides significantly less battery draw. This significantly extends battery life and is the case for most normal riding conditions. We are generally seeing up to 12 hours of run time in average riding conditions on day flash mode.

Can I use CarBack if I don’t have a compatible bike computer?

Yes, Trek CarBack can be paired with a phone with the Trek Accessory App (iOS and Android). The app will display approaching vehicles and can also inform riders of approaching vehicles via audio alerts.

At what distance will vehicles be displayed on screen through the Trek Accessory App?

Vehicles recognised beyond 150 m/500 ft will show as static triangles below the 150 m/500 ft line. Once these vehicles are closer than 150 m/500 ft, they will appear as approaching vehicles on the screen.

How do I connect my CarBack device to the Trek Accessory App?

After downloading the Trek Accessory App, tap ‘Get Started’. Follow the on-screen instructions to locate and connect to your CarBack radar. Be sure to allow any Bluetooth connection prompts and verify your phone’s Bluetooth is turned ON. Select your CarBack radar and it will begin pairing with your phone. After connecting once, the app will automatically pair with your CarBack radar on your next ride.

Does the Trek Accessory App work with other models of Radar lights?

No, the Trek Accessory App is designed to work only with the Trek CarBack Radar Light.

Can I connect to the Trek Accessory App and my Garmin/Wahoo head unit at the same time?

Yes, connecting your CarBack device with a Garmin or Wahoo head unit via ANT+ and the Trek Accessory App via Bluetooth, at the same time, is possible.

Does the Trek Accessory App work when in the phone’s background?

Yes, the Trek Accessory App can provide audio alerts while running in the background. If you turn off your screen or put your phone to sleep with the app running while connected to CarBack, you will continue to receive audio alerts as to your set preferences.

How can I control the volume of vehicle alerts in the Trek Accessory App?

If you have sounds enabled and your phone is not muted, the vehicle alerts from the Trek Accessory App will match your phone’s volume setting. If you want louder or quieter alerts, adjust the volume of your phone.

Why are Bluetooth permissions requested in the app?

Bluetooth permissions are needed for the app to connect and communicate with the CarBack device.

Can multiple GPS units connect with CarBack through ANT+?

Yes, multiple GPS units can all connect to a single CarBack unit and all get the same alerts delivered.

What is dual axis detection?

Dual axis detection refers to CarBack’s ability to identify not just the distance behind the rider of an approaching vehicle, but also whether the vehicle is directly behind the rider or to the left or right of the rider. This features requires use of the Trek Accessory App.

At what distance is dual axis detection available?

At a distance of 75 m, CarBack is able to determine a vehicle’s relation to the rider in both x and y distance and show it visibly via the Trek Accessory App.

Does dual axis detection work on GPS units?

No, the Trek Accessory App is required to display approaching vehicles and their positions relative to the rider on both the x and y axes.

Why does my phone screen dim when I'm on the Ride Screen of the Trek Accessories app?

If you're on the Ride Screen and no vehicles are detected, your screen will auto-dim to save battery. When a vehicle is detected or when you tap the screen, your phone will return to normal brightness.

Can I change the flash pattern of my CarBack in the Trek Accessories app?

At this time, the flash pattern cannot be adjusted via the app.