There are now a number of ebikes equipped with radar systems which warn riders of vehicles approaching from behind. If your bike isn’t among those, you can now change that by slapping on Garmin’s Varia eRTL615 radar/tail light module.
The unit mounts on the seat post or rear rack, facing backward just like a regular tail light. It gets wired into the ebike’s electrical system, so battery-charging won’t be an issue.
As the rider pedals along the road, the eRTL615 sends out radar pulses which echo off any cars within a distance of 150 yards (137 m) behind the bike. The module receives those echoes and analyzes them to determine how far away each vehicle is, and how fast it’s closing in.
The user is warned of these vehicles via visual and audible alerts on their wirelessly linked Garmin smartwatch or Edge cycling computer, or (more likely) via the Varia iOS/Android app on their paired smartphone. An onscreen display shows how many cars are back there, and how far away each one is.
The tail light portion of the device is no slouch itself, as it can be set to four different output modes, and has a maximum output of 65 lumens. It also starts flashing more rapidly as drivers get closer, making them aware of their proximity to the bike.
As far as other specs go, the whole thing tips the scales at a claimed 1.8 oz (51 g), it communicates via either the ANT+ or Bluetooth Low Energy wireless protocols, and is IPX7 water-resistant – that means it can withstand being submerged to a depth of 1 meter (3.3 ft) for up to 30 minutes.
The Varia eRTL615 is available now via the Garmin website, and is priced at US$299.99 – it’s demonstrated in the video below. Riders of non-electric bikes should take note, Garmin also offers a battery-powered version of the device.
Garmin | Varia eRTL615 | Rearview Radar and Tail Light for eBikes