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Garmin Varia Radar RTL515 Tail Light Review

When we consider cycling safety there are our obvious, go-to considerations. Helmet? Check! Headlights and tail lights? Check!  Visible clothing? Check! Frequent use of hand signals? Check, check, check! 

There are so many obvious ones, but what about the safety measures that aren’t as well-known, or as obvious? What about bike radar? If you are thinking, “Ummmm…what on the earth is THIS? Do I really need it?” then read on!  

The Garmin Varia Radar is a bluetooth device that lets you know when cars are coming up behind you.  Additionally, the RTL515 version has a tail light that makes it easier for those cars to see you. 

Many cyclists think that having bike radar is akin to having a bike computer. It’s a nice addition, but probably not 100% necessary. 

Honestly, I used to feel this way too. I originally purchased the Varia mostly because I wanted a really solid tail light. 

You see, I have spent a great deal of money on tail lights over the years.  I am not sure if the problem is with me, or with the lights I keep buying, but I always have a hard time finding one that holds a charge. 

I decided to go out and get myself the tail light to end all tail lights. Since I heard there was a version of the Garmin Varia with an excellent tail light built right in, I decided to give it a go. 

The price was steep, but as I cycle more and more I find myself seeking out fancier gear and higher priced equipment. Ultimately, when it comes to safety, I find that this is where my money is really well spent.  All the faster gearing and fancy carbon in the world isn’t going to do much for me if I am in a terrible accident. 

Wondering if the Garmin Varia Radar Tail Light is worth the cost? Looking to see if it’s right for you? Curious if it really increases safety on the bike?

If so, read on for our detailed review of the Garmin Varia Radar RTL515 Tail Light! 

Review in a Nutshell


  • It is one of the most innovative pieces of safety technology on the market right now. 
  • You can see traffic coming up behind you directly on your bike computer or smartphone.
  • The Varia Radar Tail Light is very easy to pair with your bike computer. 
  • It is incredibly easy to mount on your bike and the directions to mount it are very easy to follow. 
  • It is compatible with most road bikes (In other words it will easily mount on and fit around most road bikes). 
  • The tail light is VERY bright and has different modes to suit your needs. It really helps with visibility. 
  • It has up to 16 hours of battery life. I have never had it die on a ride, even a longer one as long as it’s fully charged. I can usually get a couple rides out of one charge. 
  • It can be used with a smartphone/even some non-Garmin bike computers like Wahoo.
  • It has a “Peloton mode” so that it makes the light a little less annoying to other cyclists while riding in a group.  


  • The price. This is by far the biggest con and what kept me from purchasing it for some time. 
  • The entire unit IS long and just fits under my saddle bag. I imagine taller riders won’t have this problem, but I am short (5’2”) and ride a small bike (47cm Trek Domane). It’s possible anyone shorter than me or with a lower saddle height could have a problem. 
  • Others in your household (ahem, my husband) may like it so much that they borrow it frequently. Luckily he is a very responsible borrower who always charges it up when he’s done! 
  • On some modes in very high traffic areas it can get annoying when there is a lot of traffic. 

Price & Where To Buy:

Very Easy to Pair With Your Bike Computer or Smart Phone 

To say that I am technically a bit challenged is the understatement of the year. I always struggle with tech, and bike technology is no exception. 

I honestly had absolutely no problem what-so-ever charging the Varia Tail Light and synching it with my Wahoo bike computer. My bike computer immediately recognized the bluetooth device. 

All you have to do is make sure the device is on, go into settings/sensors, select the Varia, and add it.  Every time I ride as long as the Varia is on it immediately pairs with my Wahoo. I can tell it is paired because a grey bar shows up on the side of the screen of my bike computer. 

I have never once had to initiate the pairing again. The bike computer just recognizes the Varia and I am ready to go! 

Though I have not tried pairing it with any other device, and I can only imagine that it pairs just as easily, if not easier with Garmin bike computers or with a smartphone. 

Simple Setup Right Out of the Box

I was able to very easily mount my Garmin Varia Radar Tail Light right onto the back of my bike. It comes with a few different sized mounts to fit different bike seat posts. 

I quickly selected an inner mount that bit my bike post, and then simply stretched the included band around the post to secure it to my bike.  Honestly, I am not great at attaching things to my bike (kind of like I am not great with tech) so if I say this is easy? It truly is easy. 

Once you have the Garmin Varia Radar Tail Light turned on, you are done. This device does all the rest. 

A grey bar is now visible on the left side of the screen. As a car comes up your bike computer will beep to alert you (it even has a more urgent beep pattern if the car is coming fast). 

The grey bar on the left is where the car icon will appear when a car is behind you.

You will then be able to see a little car moving up the grey bar to indicate how close the car is to you. 

As the car drives by you, it disappears from the display. That’s truly all there is to it! And all the while the light is on to alert drivers to your presence. 

The Varia Radar Tail Light is Compatible With Smartphones, Garmin, and Wahoo Bike Computers  

The first thing that I researched with the Varia was whether or not it would work with my Wahoo bike computer.  As much as I wanted the safety technology, I was not about to sacrifice my love for my Wahoo ELEMNT, nor shell out the money for a Garmin bike computer. 

I was thrilled to find that it was not only compatible with the Wahoo but also with smartphones. It is even compatible with the RideWithGPS app!

With all of the different software pairing options, the Garmin Varia Radar Tail Light makes it easy to use with your favorite smartphone app or bike computer. 

Great to Use as ONE of Many Pieces of Safety Equipment…it is NOT a Substitute for Being Aware of Your Surroundings   

I cannot stress enough that as awesome as it is to see cars coming up behind you, this is just one of many safety features and precautions that you must take on the road. One can see how it would be VERY tempting to assume there is no one behind you if the radar doesn’t indicate anything, but you cannot rely on this alone.

Varia on Bike 1

Always be sure to look over your shoulder in addition to checking your radar. Additionally, I would like to note that I can almost always hear a car before it shows up on my radar, which means that using our senses continues to be really important. 

I have a friend who loves the idea of the Varia because she is single-sided deaf, but I also know that she would also be sure to look over her shoulder before pulling out into traffic as well. 

It Really IS Expensive 

It is hard to get past the price tag of this technology. Yes, it’s true, it is radar, it is pretty accurate, and that’s amazing, but it’s still about $200. 

You can get the radar itself without the tail light for around $150, but that is still pretty pricey, AND you are going to have to find a way to mount the tail light in addition to the Varia.  At the end of the day I do really feel it is worth it, but I understand that the price tag may put it out of the range of possibility and acceptability for many cyclists. 

Bottom Line

Even though I spent a good deal of money on this product, I have never once regretted the purchase. There is something to be said for a high-end safety feature that does exactly what it says, and does it with ease.

I have personally not had the same luck with Garmin bike computers, and have found them to be rather cumbersome, so the fact that the Varia is just SO easy to set up is just one of the many reasons I highly recommend this product. 

As someone with an old neck injury from a car accident that makes it hard for me to turn my head easily to the left, I must say that having the added safety of the Garmin Varia Radar Tail Light makes me feel so much better about pulling out into traffic. 

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About The Reviewer

stacy smith

Stacy Ann Smith is a New England-based cyclist who strives to stay upright on her bike.  She is the founder of Sascy Cycling, and her mission is to encourage women to love their body and focus on what it can do, not what it looks like.  When Stacy’s not cycling she is teaching high school history and eating pizza with her husband and son. For awesome women’s cycling tips and to learn more about Stacy, visit Sascy Cycling at

2 thoughts on “Garmin Varia Radar RTL515 Tail Light Review”

  1. You might want to try rotating the mount or using one of the other mount inserts to allow the Garmin to sit in a more or less vertical position. You may then find that the radar detects cars coming well before you are able to hear them.

  2. Thanks for your review. I agree with the other commenter. The light is not set up correctly in the photos you have provided. It should be vertical. As it is currently positioned, it will not be effective at all. Cars won’t see the light and the radar will not detect them as early. Please look at Garmin’s instructions, mount the light correctly, and please show it correctly mounted in your photos for the benefit of anyone else that reads your review.


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