Radar lights

Garmin Varia Radar achterlicht zwart

The Garmin Varia Radar is a black rear light with a radar. It warns you of vehicles approaching from behind through a paired bike computer or watch.

What you get

Rear radar light from Garmin
Varia Radar model
Black colour

Why a radar light?

On a bike, the most dangerous thing is what you cannot see. A radar light looks behind you for you. It measures the distance and speed of approaching traffic, usually up to about 140 metres, and shows an alert on your screen with the number of vehicles and how fast they are closing in.

You notice it most on quiet country roads and on group rides. You know whether you can safely move out to the left, how long your view is clear and when it is better to tuck right on a wide road. Some models also make the light brighter or change its flash pattern when a car approaches, so the driver notices you sooner.

A radar light is still a rear light, with every benefit of one. It typically lasts 6 to 15 hours, depending on the mode. That is shorter than an ordinary light, so the more long rides you do, the more you need to keep an eye on charging.

It detects what comes from behind. It does not see vehicles from the side or riders passing you at very short range, and it can miss a signal at very low speed or on a small bike. It does not replace your own glance over the shoulder.

How a radar light compares with an ordinary rear light

A radar light does more, but asks more of battery and pairing.

Type	Warns you	Seen from behind	Battery	Note
Radar + bike computer	Yes, on the bars, up to about 140 m	High, adapts to traffic	About 6 to 15 hours	Computer must support the system
Radar + phone app	Yes, on phone or watch	High	About 6 to 15 hours	Phone must stay on and close
Ordinary rear light	No	Good, varies by model	Often 8 to 30+ hours	Simple and light
Rear light with brake sensor	No, but it shows when you brake	High, with brake mode	About 6 to 20 hours	Useful in groups and on descents

Range and runtime vary by model and mode.

Choose it if

You ride a lot on roads with traffic and want to know what is coming from behind
You own a compatible Garmin device to show the alert
You often ride country roads or out of town, with cars passing at speed.
You ride alone or in small groups a lot and want to know what is coming up behind you.

Choose something else if

You have no compatible device, so you would not use the radar fully
You mostly ride in town at low speeds, where an ordinary light is enough.
You do not have a compatible device to show the warning.

How to use a radar light

Charge it
Charge the light fully. The radar uses more power than an ordinary light.
Fit it pointing straight back
Clip it to the seatpost, roughly upright and clear of any saddle bag or jacket. The radar needs a free view of the road.
Pair with your computer or app
Search for the light as a sensor on your bike computer or in the app. Check that the warning appears on screen.
Watch the warning
A bar or colour change shows approaching traffic. Use it as an aid and keep looking around yourself.

Good to know

Check that your bike computer or watch can pair with the radar
Charge the light regularly, as it runs on its own battery
Check that the light is compatible with your bike computer or app. Not every system works with every device.
Look at the runtime in the mode you use. With the radar active it is lower than with an ordinary light.
A radar sees vehicles from behind, not from the side, and not everything at close range. Keep looking yourself.
Keep the lens clean. Dirt or spray can disturb the detection.

What you get

Why a radar light?

How a radar light compares with an ordinary rear light

Choose it if

Choose something else if

How to use a radar light

Charge it

Fit it pointing straight back

Pair with your computer or app

Watch the warning

Good to know

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