The Garmin Varia RTL515 is a product I consider life-changing, no really, and it’s on sale for Black Friday. If you'd rather cut to the chase, you can jump right to the deal. For those that aren’t convinced by that compelling argument, don’t worry, I've got more to say. Keep reading and I’ve got solid reasons for telling you about this, I just want to make sure we are starting with an understanding that I absolutely love this light, think everyone should get one, and never leave the house without it.
Let’s back up a bit though. I’ve been writing our buyer's guides covering the best bike lights for a few years now. I asked for the assignment after spending far too much time riding from my house deep into winter. At that time of year, it gets light late and dark early and my rides meant starting and ending with a light. I’m also the person who frequently has a new idea about riding through the night rather than carrying anything to sleep with. Regardless of my reasons though, I’ve seen and tested more lights than almost anyone. I’ve got a bin of lights that I can dig through at any moment looking for the perfect light for every situation. The Garmin Varia RTL515 is still a standout and definitely my most used light.
What is the Garmin Varia RTL515?
There are two parts to this question because there are two parts to this product. The RTL515 is one part light and one part radar. Let’s start with the light part though. This is the most straightforward.
The light section is at the top of a rounded rectangle measuring 3.9” / 98.6mm tall by 1.6" / 39.6 mm wide. Most of that space isn’t dedicated to the light though. The light itself is roughly .1” / 2.7mm round and sits behind a fresnel lens. The centre section is clear while the outer rings of the lens are frosted. There are also clear red side lenses that allow light leak and visibility from either side.
In terms of raw power, the light is not the brightest available. There are four modes available including solid, peloton, night flash, and day flash but the brightest choice is day flash. In day flash mode Garmin uses an irregular flash pattern at 65 lumens making it the least powerful light in my list of the best rear bike lights. Remember though, lumens is a measurement of power and not a measurement of brightness. Garmin doesn’t list the lux rating but does specify that it’s visible up to a 1 mile / 1.6 km away and I’m not going to argue with that. The design of the lens makes it incredibly bright and the irregular flash pattern also increases visibility.
While visibility is impressive, so is battery life. Using day flash mode you can get 16 hours from the Garmin Varia RTL515. Again though, the spec isn’t class-leading. It is on the rather impressive side of things but there are other options on the list with longer burn times.
If I've not convinced you how great the RTL515 is while running through the middle-of-the-road light specs, remember that there is another side to this product. Truly the lighting piece is impressive but it does have to be acknowledged there are others that are better and they cost less. What makes the RTL515 impressive is that it’s a good light and it comes with Garmin Varia Radar.
The Radar piece of this is the real magic. It’s the reason that the whole unit is so much bigger than the light and it’s why I never leave the house without it. It’s also fairly simple in concept.
Garmin Varia radar is simply rear-facing radar that measures speed. The sensor spread is 220 degrees and 153 yards / 140 meters and as a vehicle approaching from behind enters that space, you will get visual and audible alerts (depending on your settings) on your bike computer. In practice, the distance is actually more and it will also detect multiple vehicles.
What is the Garmin Varia RTL515 like to use?
So you’ve got a light and radar that mounts to the rear of your bike via a Garmin quarter-turn mount, now what? You’ll mount it either via the included rubber band mounts, or via a huge variety of third-party mounts, and you’ll turn it on plus connect it to your bike computer via ANT+ or BLE. That might not seem that groundbreaking yet but there’s a lot of nuance.
Again I can start with the light part of the equation. The RTL515 supports the Garmin light network system and when paired to a Garmin computer, that opens up a greater experience. You don’t have to use a Garmin computer with this piece but if you do, you’ll never have to turn it on or off. Instead, you’ve got the option to have it turn on with your head unit or when you hit start and you can also decide what mode it turns on with.
For me, I leave it to turn on and off when I start and stop a ride and to operate in the day flash mode. I never have to blind anyone as I walk through my house and I get the most visibility paired with the longest battery life.
Part of that system though, is choice. Instead of having to press buttons on the light itself, I can adjust its behaviour from my bike computer. When I do rides I expect will be longer than 16 hours, I take advantage of this to extend the battery. In the morning when I start I’ll let it do its thing as normal. As the sun rises, I’ll switch the light off but leave the radar on. At night I’ll go back to the flashing light. I’ve managed over 24 hours with the system.
The reason I care about leaving the radar on is the other piece of this puzzle. It takes some time to really grasp what this is like but once you do, this is the life-changing piece. Remember, it works by telling you there's a car behind you. That’s a lot like a mirror and it’s so good that you can indeed use it that way. When there’s one car it will sometimes not “see” a second right behind but other than that, it doesn’t miss cars and it doesn’t falsely alarm. It is so reliable that I watch my head unit first, then double-check when I want to move across a lane. I never have to start by looking to see if the road is clear with a head turn.
There are some other knock-on effects of that as well. Namely, you can relax while you ride. If you are with a friend, you can ride two up and chat away until there’s a car coming. If you ride alone you can lose yourself in your ride instead of listening for approaching vehicles. Once you are used to it, it changes your whole relationship with traffic.
Garmin Varia options
I’ve only run through the RTL515 because I love it and think everyone should have one. That said, there are other Varia options. Typically the least expensive is the Varia RVR315 but I don’t recommend buying it. At the moment it’s not on sale so it’s the same price as the RTL515 but has less battery life and no light. More interesting though, the Varia RCT715 adds a camera to the equation. I did a full Garmin Varia RCT715 review and it’s an intriguing piece of gear which is also on sale right now. I tend to use it less because it’s got less battery life but if you ride shorter distances, and like the idea of having a traffic camera with you, it’s worth consideration. You get all the benefits of the RTL515 plus a better mount and the camera.
Whatever you decide on, Garmin Varia is something I use and love. When I write a buyers guide or do a review, I put on my reviewer hat. I look at the market and put myself in other people’s shoes. Is a product well made and priced fairly with a concept that makes sense? If so, it doesn’t always mean it has to be for me. On the other hand, I ride around 10,000 miles / 16,000 km a year and I have lots of options when it comes to lights. The rear light I never ride without is the Garmin Varia RTL515 and it’s on sale. Go grab one.
Deal links
If you've gotten this far, then you're clearly an avid deal-smith, so why stop now?
The list below overviews our ecosystem of articles dedicated to finding the best deals available. We've got deals pages tailored to road bikes, electric bikes, clothing and more, as well as retailer-specific deals pages such as Wiggle. We've even got a page dedicated to GoPro cameras.
- Black Friday bike deals: Our central hub of all the cycling deals this year
- Black Friday bike helmets: Safety on a budget for road and off-road use
- Black Friday cycling clothing: Kit out your cycling wardrobe without paying a fortune
- Black Friday cycling shoes: Save on summer and winter kicks
- Black Friday electric bikes: Power your way to savings
- Black Friday gravel bikes: Gravel grinding doesn't have to cost a fortune
- Black Friday kids bikes: They grow so fast, so don't pay full price
- Black Friday turbo trainers: Everything you need to get Zwifting on a budget
- Black Friday Castelli: Save on winter kit just as winter takes hold
- Black Friday Garmin: Smartwatches, cycling computers and more
- Black Friday GoPro: Shoot for the moon with top-quality action camera deals
- Black Friday Rapha: Big deals on the British clothing brand
- Black Friday Wiggle: One of the world's biggest cycling sales
- Black Friday Wahoo: The best prices on Wahoo's range of cycling tech
