Garmin Varia RCT715 radar camera rear light review

Garmin’s Varia is an on-bike radar system that detects approaching vehicles from up to 140 metres behind you. This is said to improve rearward awareness on the road, while the linked light responds to increase your visibility.

The RCT715 adds a high-definition camera to the mix, now making it an incident-recording device too.

Testing shows the concept is sound and the unit very usable, although work is needed on the post-ride experience to make the RCT715 a firm recommendation.

Garmin Varia RCT715 specifications and details

The RCT715 is a big unit for a light, weighing 148g on my scales (1g more than claimed) and measuring 106.5x42x31.9mm.

This is in addition to a chunkily proportioned mount. It’s not identical to the quarter-turn mount used for Garmin’s bike computers, but the added heft makes it even more secure.

It feels well-made in hand, and has an IPX7 waterproof rating, which is enough to guard against limited submersion.

You can connect the system to a Garmin bike computer (or compatible GPS), or by using the Varia app on a smartphone.

In use, the smartphone app presents a scrolling screen that shows when vehicles are approaching from behind, plus a live representation of their distance from you.

The vehicle icons change from green to red as they get closer, and the Varia’s rear light brightens as they approach.

On a Garmin bike computer, the screen shows a narrow sidebar, which represents the vehicles as dots progressing up the display. It can also give you audible warnings.

The light can be set to four basic modes: Solid (20-lumen output), Peloton for group riding (8 lumens), Night Flash (29 lumens) and Day Flash (65 lumens).

Meanwhile, as vehicles approach, the output from the light spools up and flashes to improve your chances of being seen.

Garmin says you can expect 4, 5, 3 and 6 hours of battery life respectively – the Day Flash mode being more staccato in its flash pattern than the less powerful Night Flash setting.

The difference between the RCT715 and the previous Garmin RTL515 is the inclusion of an onboard video camera.

The camera records in high definition (1080p), at 30 frames per second.

When switched on, the Varia RCT715 can record constantly or upon command.

During constant recording, when an incident is detected, it automatically saves the footage in a minimum 90-second clip that includes the riding immediately before, during and after that moment of detection. The unit also locks the footage so it can’t be deleted accidentally.

You can also self-select the moments you want to save (for example, potential near-misses), from the app or bike computer.

The unit detects these incidents using a built-in gyroscope and accelerometer, which can detect sudden deceleration.

Garmin Varia RCT715 performance

I found the radar element very useful during my test rides, especially at night when I really needed to be keeping my eyes on the road ahead rather than looking over my shoulder repeatedly or for extended periods.

The radar is an excellent aid when you want to pull out into the centre of the road to make a turn across traffic and need to keep your eyes focused on what's in front of you.

The audible warnings are also useful, although I found they got annoyingly frequent when riding in heavy traffic.

None of this negates the need to look behind you, be aware of your surroundings or indicate appropriately, but it adds some reassuring extra knowledge when you want to manoeuvre.

The light is excellent, producing a bright and rich emission that calls into question whether you really need a rear light that delivers three or four times the lumen count.

The side-windows in the unit provide a bit of welcome side-on visibility too.

The camera part of the equation provides decent-quality footage (especially in 1080p mode – you can also record in 720p resolution if you wish).

It can be set to record constantly or trigger a recording automatically on detecting an oncoming vehicle.

From a Garmin bike computer, when the Varia is set to record constantly, you can save an instant photo of the view behind, or save a video clip anywhere from 90 seconds to five minutes in length (in 30-second increments).

It’s worth bearing in mind that battery life is drained much faster if you're recording constantly or frequently saving clips.

On a 30-mile steady commute to my office from home, the battery was empty after 1 hour 20 minutes.

Garmin includes a 16GB microSD card for use in the Varia, which (broadly speaking) can deliver up to two hours of footage at 1080p, recording at 30 frames per second.

This should be more than enough if you’re using the Varia solely from an incident-recording perspective.

Incidentally, the Varia can accommodate a 512GB-capacity microSD card, although the Varia app is limited to handling 128GB of footage.

In practice, the 140-degree field of view captures vehicles approaching well. It records usefully stable footage and the detail is good enough to identify vehicle plates even in low light.

In short, it should produce usable evidence should the worst happen to you while out on your bike.

A GoPro rival?

At launch, Garmin claimed the Varia RCT715 is also suitable for recreational recording.

In the vast majority of cases, action-recording riders will be better off looking for something dedicated to that purpose.

The Varia’s image stabilisation – albeit good enough for incident recording – can’t match the latest action cameras or even some of the best budget cameras.

Some cameras also feature higher resolutions and frame rates, while the RCT715 is fundamentally designed to face rearwards (an obvious limitation).

This means it’s not such a cost-effective alternative (to tie in camera, light and radar functionality) as it might seem when compared to a dedicated camera.

That said, the retained footage can be overlaid with the date, time, GPS information and speed – elements of which can be a nice addition to action camera recordings.

However, it’s clear these are geared primarily towards providing supporting evidence in the case of an incident.

There are flaws. In testing, I found that my Garmin head unit had a much smarter incident detection than the RCT715 used in isolation.

When used without a connected bike computer (or smartphone), it was too easily triggered to save recorded video by simply stopping quickly, dropping off a kerb, or hopping a speed bump.

Then, after a ride, if you do have footage you want to extract, the user experience gets somewhat clunky (especially if you have to sift through stacks of video clips of you braking hard or going over a bump in the road).

Thanks to a local WiFi connection between the RCT715 and your phone, you’re able to look through the series of clips stored on the unit’s memory card.

However, downloading them is a sluggish affair, taking just shy of four minutes to download a 90-second clip to your phone’s camera roll.

If you’ve ridden in either continuous mode or in heavy traffic with the camera triggered by approaching vehicles, you'll end up with a mountain of video clips.

This results in the phone app working sluggishly and being very slow to create thumbnails as you scroll down the timeline. Download times are similarly pedestrian.

This is compounded by the fact that when you find the clip you want – and you’ve played it back to make sure it’s the correct one – you then need to download it to your phone.

This takes much longer than it should, although a recent app update (2.2.0 19) has improved matters somewhat. Still, faster download speeds is a goal Garmin should continue to pursue.

Garmin Varia RCT715 bottom line

Overall, I like all of the Varia RCT715’s functions and it will do a good job of acting as an all-in-one safety camera light.

The light is bright and has a good number of useful settings. The radar functionality remains useful and is a meaningful aid to your awareness on the road.

The camera is also fit for purpose. The footage quality is ample, albeit the RCT715 is best used as an incident-recording device rather than an all-in-one action camera.

However, the way in which the app and unit handle recorded footage leaves something to be desired. Hopefully Garmin can further improve and address this in later updates.