Last summer, I picked up a Garmin Varia to review for a local bike shop. Then, something unexpected happened. Instead of giving it back, I bought it. And paid full price. The Garmin Varia radar taillight is the 1% I’ve been looking for.

Testing the Garmin Varia RTL515

The Varia is a rear-facing radar that alerts riders of traffic approaching from behind. With audible and visible cues relayed to your GPS unit or Garmin watch, you can actually see a car close in and overtake in real-time. The system works extremely well, picking up cars over 100 meters away in rolling terrain or on winding roads. The Varia remains the best radar taillight on the market, and its closest rival is its own baby brother.

The Two Garmin Varia Options

When Garmin rolled out their new Varia last year, they also offered up the RVR315. That version is not a taillight, but it is a rear-facing radar that functions much the same way. The benefit is that you can use it with any taillight, but for most riders, having one thing clamped onto their bikes, not to mention only one thing to keep charged, is worth the extra cash.

The RTL515 is a nice taillight that offers the multiple flash/steady blinking patterns you’d expect from any taillight. The big improvement on this model of the Varia is extended battery life, and while I can’t say for certain if it’ll actually make it 16 hours in flashing mode as it claims, I can usually get a week or more out of the light for rides and commutes. DISCLAIMER: I don’t ride that much anymore.

Garmin Varia Compatibility

One of the biggest limitations caused by previous editions of the Garmin Varia was the ecosystem. The ‘walled garden approach’ meant Varias did not pair with bike computers made by other manufacturers.

So does this Garmin Varia work with Wahoo?

It sure does, but with an asterisk. The Garmin Varia is compatible with Wahoo, Sigma, Hammerhead, and other GPS units, but it certainly isn’t the same experience. The Varia works exceptionally well in spotting cars and giving me a heads up, but I will say that the adjustable settings available when paired with a Garmin Edge are far superior. Check out DC Rainmaker for a much better look at the display difference.

Using the Varia for Commuting

I thought I’d hate it but being able to pair my Varia light to my Garmin Forerunner 245 (hey, I jog a little) is really useful for commuting. Knowing when cars are close behind, especially coming up to intersections, is a huge help. The light also flashes brighter as they get close which, at least anecdotally, seems to be enough to earn me an extra inch or two before they pass.  

The Drawbacks of the Garmin Varia

Ironically, the drawback of the Garmin Varia isn’t the light itself, it’s the mount. If you’re trying to get the light on an aero seat post, you’ll have to devise a shim to make sure it stays centered on the flat section of your post. I can’t tell you how many times Kent, the guy who introduced almost all of TC to the Varia, said, “Your light is turned sideways again” just minutes into a ride. The light stays more secure (and straight on normal round seat posts, but I have noticed that they slide down. The Varia comes with two mounts, so plan on experimenting to find the right one.

Shop Local

Is it a good buy? When it comes to anything safety-related, I go by the 1% rule. If a product offers a 1% increase in reducing an accident or reducing the severity of a crash, it’s worth it. The idea is that 1% many times over adds up; the right helmet, the right flat kit, the right bike maintenance, the right bright colors…it all makes a difference.

If you’re interested in a Garmin Varia, give your local bike shop a shot, and maybe get in touch with one of our sponsors.

Want more kolo t.c. news, rides, and reviews? Sign up for Off the Back, the weekly digest featuring cycling stuff from around the internet!