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Garmin Varia RVR315 vs RTL515 Review: Why I Won't Ride Without It

After getting hit by a car, one of the best ways I’ve found to restore my confidence is a Gamin Varia. This radar device watches out for cars and I can’t live without it. Here’s why.

Written by: Bruce Lin

Published on:

Posted in:Road

For months after getting hit by a car, my rides were tainted by paranoia and nerves. Getting buzzed by a driver is frightening, even if you’ve never been hit. Fortunately, I’ve been able to recover and in that last couple of years I started having fun riding on the road again. 

These days, I wear high visibility kits and stick to less trafficked routes. But one of the best ways I’ve found to restore my confidence is a Gamin Varia. It may sound like a gimmick, but this radar device watches out for and warns you about approaching cars. It improves your situational awareness and allows you to ride more defensively, while still focusing on the road ahead. And it really works. After riding with it for a full season, I realized that I can’t live without it. Here’s why. 

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What is the Garmin Varia?

The Varia attaches to your seatpost (or saddle/saddle bag with aftermarket mounts) and uses radar to detect cars are approaching from behind. 

Garmin Varia RTL515The Varia connects to a compatible head unit (Garmin, Wahoo, Hammerhead, and Stages are all compatible) or smartphone app using ANT+ or Bluetooth. When the Varia detects an incoming car, your head unit gives you an audible alert along with a graphic that indicates the car’s distance and speed. Cars are presented as individual dots moving up the side of your head unit’s screen. The Varia detects cars up to eight cars from as far away as 140 meters. 

The edges of the screen also change color to indicate overtake speed (i.e. the difference in speed between you and the car). Yellow-to-orange indicates a “normal” passing speed. If a car is going fast enough it will trigger a more noticeable alert tone and the screen will show red to warn you so you can react appropriately. Once there’s no more traffic behind you, the screen turns green. 


Garmin Varia RCT715 vs. RTL515 vs. RVR315 comparison

Garmin Varia Comparison









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The Varia comes in three different versions, but the two models the majority of riders will be interested in are the RTL515 and RVR315.

The two main differences are an integrated tail light and battery life. In both cases, the RTL515 is superior. Its light is ANT+ connected, so settings like brightness and blinking can be controlled from your head unit. The RTL515 battery lasts up to 16 hours in day flash mode.

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The RVR315 provides 7 hours of battery life. It is a good option for riders on a budget, riders who already have a preferred tail light, or those who don’t want a light for situations like races or group rides.

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For those who want all the bells and whistles, the top-spec Varia RCT715 adds a rear-facing camera. This is handy for recording your rides, and if the worst happens, it will keep a video record of any incidents. If you're interested in the RCT715, check out my more detailed Varia RCT715 review

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Currently, the RTL515 is my go-to, and it's the model I've purchased for all of my family members who ride. It doesn't cost significantly more than the RVR315, and the addition of a bright taillight only enhances safety by increasing your visibility to motorists. The longer battery life is also a definite plus.  

All Varia models come with mounts for round, aero, and D-shaped seatposts and are easy to install and remove with Garmin’s standard quarter-turn mount. 

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Do you need a Garmin Varia? 

You don’t necessarily need a Varia to ride safely. You can turn your head and look behind. As long as you ride without headphones you can usually hear cars approaching. And if you want to be extra safe, you can attach a mirror to your helmet or handlebars. But you can’t look behind you for an entire ride. Once you’re riding above 15mph, wind noise makes hearing cars harder. And a mirror is only effective if you’re paying attention to it. 

Garmin Varia car radarEven if your mind wanders during a ride, there are never gaps in the Varia’s attention. It detects cars long before they can be heard, so they will never catch you by surprise. 

How does the Varia keep you safer?

The Varia isn't a force field. It isn't going to prevent an errant car from hitting you (hopefully, one never does). It is also not a substitute for staying attentive on the road and using common sense. Its purpose is to give you extra information and awareness so you can ride defensively. Here's how the Varia helps me stay safe on the road:

  • Since I always know a car is coming, often before I see or hear it, I can adjust my position on the road early to create the safest passing situation.
  • When riding in a group, the audible alerts are useful for warning the whole group about approaching cars. We can make room or move to single file before the car is on us. 
  • Speeding cars are what you really need to worry about. When the screen goes red and I hear the high speed differential alert, I can get over early and look back to see what the car is doing. Those cars and drivers scare me the most, and knowing about them early helps me brace myself. 
  • Because the Varia can pick up multiple cars at once, I can watch a line of cars approach and pass me on the screen. I know their position relative to me, even with looking, so I know exactly when I'm safe and clear. 
  • Lane changes, turns, and taking the lane are much less stressful with the Varia watching your blind spot. 
  • I no longer have to do constant head checks behind me while riding. Occasional head checks are still good practice, but I can focus more on the road ahead. 
  • The Varia can pick up approaching riders too! Cyclists can be hard to spot, even for cyclists. I've had the Varia prevent me from getting spooked went getting passed by faster riders. 

For me, after being struck by a car, the added confidence alone makes the Varia worth the price. I'm no longer surprised by speeding cars buzzing me too close. I know exactly when I should leave space or take the lane. I can change lanes and make turns with total confidence. Once you’re accustomed to the increased situational awareness the Varia provides, you’ll realize how little you can see without the extra "eyes" it gives you.

In an ideal world, motorists always see cyclists and treat them with respect. But because we can’t control the cars around us, I think all riders can benefit from a tool like the Varia that lets them keep tabs on their surroundings and gives them a better chance of avoiding incidents.  

Best of all, the Varia is simple and unobtrusive. It easily connects to different head units and I can swap it between bikes in seconds. Using it has become second nature. To me, it’s now the most important piece of safety equipment I use after my helmet. 

Pro tip: If you have a Garmin head unit and a friend with a Varia, you can actually try it out before buying. The Varia can connect to multiple Garmin Edge head units at once. This is actually how I discovered the Varia and became convinced! 

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Images courtesy of Garmin