Trek has just lifted the veil on a nifty tail-light/bike radar combo. In the same vein as the Garmin Varia or Magene L508, it combines a powerful daytime visible light with a rear-facing radar that picks up cars as they approach, showing a representation of the distance and speed on your head unit, smartwatch or smartphone. Whether you’re using it on a gravel ride, pedalling over to your local trails from home, or on your commute, it’s a nifty little light.
An Overview of the Trek CarBack Radar
The CarBack combines the brand’s Flare RT tail light, which is claimed to be visible from up to 2km away in daylight, with a radar unit that claims to pick up approaching cars as far away as 240m.
Trek says the CarBack is supported by most cycling computers, GPS smartwatches, and smartphones. We paired it with a Garmin Edge 830 computer, an older Wahoo ELEMNT Bolt, and a Giant/Stages Dash L200 without issue.
At the time of writing, the Trek Accessory App had yet to go live in the Australian App Store, so we haven’t had the chance to play with that just yet. But Trek says it allows for dual-axis detection, showing not only a car approaching and at what speed, but also how close the driver will be when they pass.
Once paired, as a car approaches, a little icon lights up on the side of your head unit and gets closer as the car draws nearer. There is an audible tone, and a colour change depending on how quickly the car is driving.
It attaches to your seat post using a simple rubber band and can be removed via a sliding clip interface for charging — which uses a USB-C plug.
How does it compare to the Garmin Vaira?
The Garmin Varia is arguably the biggest competition to the CarBack and has been something I have used more or less since it was launched. On long gravel rides and commutes, it seems to pick up cars well before I can hear them, and their bright blinky lights are packaged into a well-finished unit.
The Trek does this as well, but in a smaller, more compact package. The mounting interface is a little different, with Garmin leveraging its trademark quarter-turn system. However, the simplicity of the rubber band on the Trek fits better non-round seat posts — like the D-shape post on our Canyon Grail test bike.
On the box, Trek claims the battery life to be 7 hours regardless of the brightness or flashing setting. We asked Trek AU about the run time, and it said radar is the most significant battery drain, and the team tested the CarBack at worst case, always-a-car-in-range, radar use. Trek predicts up to 10-12 hours on a single charge in more realistic conditions. The Garmin will go for up to 16 hours on Day Flash mode.
Regardless of the actual battery life, the CarBack sees a simple LED battery gauge, which the Garmin does not have.
The Trek also claims the light is visible from 400m further away, and the radar is sensitive to 100m further out. Priced at $299.99 AUD, it’s also $70 AUD cheaper. It’s difficult to test the visibility and radar claims—both lights create a super-focused beam you can see from well off, and the radar picks up cars before your ears do. While the Garmin well and truly wins the battery life competition, we think the price difference is likely enough to sway folks.
