Garmin Varia RTL515 Radar Review (And Why I Won’t Now Ride Without One)

In this post I review the Garmin Varia radar system and specifically the Garmin Varia RTL515 radar rear light.

I say ‘review’ but in fact I’m afraid it’s going to feel more like a public safety broadcast, crossed with what you might assume is an advert for the device.

I bladdy love this thing. You should buy one. Right now.

Go on. Here’s the link:


Garmin Varia Radar RTL515

As well as a good rear light, the Varia tracks vehicles approaching from behind and sends alerts to my bike GPS. My favourite piece of bike tech.

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First though, if you’re new round here, you are reading the velvet wordsmithery of Sportive Cyclist, the MAMIL channel.

I write (and make videos) about road cycling.


As a not particularly fit MAMIL that likes road cycling. Next!

If you like road cycling and you’re partial to a bit of Lycra then you should definitely consider subscribing to my YouTube channel.

Garmin Varia RTL515 Review

Now before you do accuse me of taking money from Garmin, I bought this Varia device with my own money back in….


November last year. So what’s that? 4 months of use.

And I will now not knowingly ride without it.

Garmin Varia RTL515

It’s literally my favourite piece of bike tech that I’ve bought in the last five years.

Maybe ever.

But wait. The Varia is probably not the first piece of bike tech you should buy. That would be a bike computer BRACKETS that works with the Varia CLOSE BRACKETS.

After that, get a Varia.

By the way, if you want to know if and how the Varia integrates with non-Garmin bike GPSes, such as the Wahoo ELEMNT Bolt and the Bryton Rider 750, stick around til later in this post.

But Mont, what is a Varia and why so evangelical?

Ahhh, let me tell you…

A Radar For Bicycles – What’s That?

Garmin’s Varia system is basically a radar system that looks behind you. Science. And let’s you know when a car is coming. Or any sort of vehicle.

Actually the Varia range has sort of expanded into lights as well, but most people think of it as the radar.

And crazy as it sounds, again, SCIENCE, it actually works.

Garmin Varia on seat post

The Varia will connect with your compatible bike computer via ANT+. When it detects a vehicle, your bike computer will alert you and then display the vehicle’s approach on the display as it gets closer.

Once the car has passed, the bike GPS will sound and/or display visually the all clear.

If there is more than one vehicle then multiple dots, or car symbols, will display. The device will only signal the all clear once all the cars have passed.

Varia Tracks All Road Users (That Are Catching Up With You)

And the Varia won’t just track motorised vehicles. It will alert you to other cyclists approaching as well.

But since I don’t get passed on my bike [… silence… taps fingers] I cannot confirm this to be the case.

I can confirm this to be the case.

Basically, it picks up anything behind you that is moving faster than you. So if I’m fettling my bike on the drive, ahead of setting off for a ride, it’ll warn me of the approach of my daughter on her new deathtrap roller skates.

Varia alert on Garmin Edge 530

And the speed of the thing approaching, relative to your own, is important.

The Varia, or rather whatever bike GPS display you’re using, will show orangey graphics if the approaching vehicle is going at a normal speed, whatever that is.

If it’s red, then you are being pursued by a horde of marauding orcs. Or the car is just moving quickly.

How Much Warning Does It Give?

According to the Garmin website the Varia picks up cars approaching from 140m away.

I obviously haven’t measured this.

I can, however, confirm that it gives you plenty of warning.

Once a vehicle appears on the display you have plenty of time to check the road ahead, steady yourself, grit your teeth. Prepare to, how you say, flip the bird at the driver.

But Again You Ask, Why So Evangelical?

Answer: it’s just brilliant. It works really well. It’s accurate. In three months of riding, it has picked up and tracked every approaching vehicle until it has passed.

The roads where I ride are generally quite quiet. I can hear vehicles coming.

But in my pre-Varia days, maybe I’d zone out or it would be noisy with wind, and I would suddenly be surprised by a speeding car at my shoulder. It gives you a jolt.

Certainly not ideal when it happens at the same time you swerve slightly to avoid a pothole.

This literally doesn’t happen any more. I am never surprised by the sudden appearance of another vehicle.

I was half joking about giving yourself time to grit your teeth for the pass. But there is something to be said for knowing a car is there, without having to turn round, and if you need to, just shift into a safer road position.

The proof is in the pudding.

The odd time I’ve not ridden with the Varia installed – it feels a bit extreme to say I feel more exposed whilst riding, but on a road that I know is generally busier, I do notice myself having to look over my shoulder on a regular basis.

I feel happier riding knowing the Varia has my back. Or something.

Not Just A Rear View Radar – Also A Rear Light (Radar)

I’ve got this far in and I haven’t mentioned that this particular variant of the Varia, the RTL515, is also a rear light.

You can buy a rear view radar that is just the radar bit, the RVR315, but I wouldn’t.

You need a rear light anyway. There’s only so much space on your seat post – more on that topic in a bit – and the Varia rear light is as good as I need.

In fact, it’s an ANT+ light so you can control it – turn it on, change mode – using any device that supports the ANT+ light control protocol… which is basically the Garmin Edge range.

It’s nice to be able to control the light from the comfort of your own bike computer and all but this isn’t a critical feature for me. You can change between the different modes by using the button on the top.

So even if you have a Wahoo or another non-Garmin device, it’s still worth getting the RTL515 version with the light.

Talking of which, I’ve kept you waiting long enough.

What’s It Like Using The Varia With Non-Garmin Bike Computers?

In short, the Varia works great with non-Garmin bike GPSs.

I’ve used the Varia with the Wahoo ELEMNT BOLT and the Bryton Rider 750, in addition to the Garmin Edge 530. On some rides I’ve had all three of them connected to the Varia.

Bike computer compatibility with Garmin Varia

All of them pair really easily with it.

If the Varia radar is on then they’ll just start working when you’re out on a ride.

They’re all pretty consistent in how they show approaching vehicles on the screen. There’s a bar down one side of the screen with some sort of icon to denote each car.

Garmin Varia and Bryton Rider 750


Garmin Edge devices just show dots (or small circles if we’re feeling generous) to denote approaching vehicles (objects).

Wahoo and Bryton take things a little more literally by showing car icons (yes, EVEN IF IT’S A BIKE!).

Varia display on Wahoo ELEMNT BOLT


And in Wahoo’s case, if you take exception to the little cars, I believe there is a way of uploading your own icons – if such a thizzle would flizzle your bizzle.

Radar Alerts

All three bike computers handle the alerts in a similar fashion, whether audibly with beeps, or with a orange and red colour displays when a vehicle is approaching and green when it has passed and all is safe.

Actually, for choice, and I’ll admit this is marginal, I prefer how the ELEMNT BOLT and the Rider 750 show these alerts over the Edge 530.

Edge BOLT and Rider 750 with Varia alerts

The Edge has colour bars down both edges (ha!) of the screen that blend into the main display. I prefer the cleaner way that Bryton shows a simple block of colour, that doesn’t blend in.

The ELEMNT BOLT doesn’t have a colour screen. Instead it changes the colours of the LED strip above the screen as a car appears and then passes. This is really neat.

Wahoo ELEMNT BOLT Garmin Varia LEDs

(As an aside, and I don’t have either, I think you can set the side LEDs on the Wahoo ELEMNT ROAM and on the original ELEMNT to track the vehicles as they approach).

Anyway, I’m wittering on. The Varia radar functionality works great on both the ELEMNT BOLT and the Bryton Ride 750.

Things To Consider

So, you’re sold on value of getting a Varia. Are there any points of note or question marks from my side?

Perhaps a few. But none of them are dealbreakers.

Number 1: I haven’t worked out yet how to fit my Varia rear light alongside a saddle bag.

Or rather below it.

I don’t have the largest saddle bag. And I don’t think I have a short seat post. (My wife tells me it’s just right)

Varia limited space on seat post

But I can’t get both of them to fit. Particularly when the Varia instructions tell you specifically to avoid installing it too low down such that its field of vision – field of radarvision – is inhibited.

I’ll have to work out another tube and multitool carrying solution because I am not forsaking the Varia.

*** UPDATE: I’ve worked out how to attach a Garmin mount to the flap (loop?) of material on the back of the saddlebag (using the standard Garmin rubber bands). This might work for you if your own saddle sack has a similar feature. Otherwise its choices time… ***

Garmin Varia attached to saddlebag

Number 2: Battery life

If you’ve seen some of my bike GPS videos, you’ll know my battery testing protocol is based on feelz rather than actual testing.

The Varia, at least this one that is also a rear light, feels quite heavy on battery.

Garmin says up to 16 hours in ‘daylight flashing’ mode – my favourite mode but that’s nothing to do with bike lights.

(I thenk yow)

In solid beam mode it’s 6 hours.

All I can say is that it feels – that unscientific word again – as if I have to charge it quite frequently. Three or four shortish rides go by and my bike GPS is displaying a message that the radar battery is low.

Garmin Varia USB charging cover

Which makes me think, maybe I’ve just been riding around with solid beam on the whole time…

Number 3: Performance in the rain.

I will admit that I’ve not done a lot of riding with the Varia in the driving rain. Despite using it during the winter, I’ve obviously been lucky. Or weak.

I’ve seen from other reviews that whilst it is fine in light showers, it may struggle in heavy rain.

This isn’t about the waterproof-ness – it’s IPX7 so you don’t need to worry about that. But something to be aware of if you’re a fan of aquatic riding.

I have ridden on very muddy roads though. The Varia certainly doesn’t mind being spattered with good old English cow sh….

Garmin Varia in the rain

So! To Sum Up…

I’m not sure something as esoteric as a bike radar system can become a cliché.

But I’ve read this in multiple places and seen a number of YouTube video. They all say the same thing, broadly.

Before owning a Varia radar, you wonder what all the fuss is about.

Then you buy one and you wonder how you ever got along without one.

Then you go around telling all your velofriends to buy one.

Then you start a YouTube channel and make a video love letter about one.

How Much Does the Garmin Varia Cost?

I guess I should mention cost. The Garmin price is £170 for this one with the light (the RTL 515), $200 in the US. But I bought mine for £130 in the Black Friday sale, so there are offers from time to time.

It’s not exactly cheap. But in value terms to me, I’ve been very happy with my purchase. Which perhaps you can tell.

If you do want to buy one, here are the links. They are affiliate links – I’ll get a small commission but you’ll pay the same price.

Garmin Varia Radar RTL515

As well as a good rear light, the Varia tracks vehicles approaching from behind and sends alerts to my bike GPS. My favourite piece of bike tech.

Check price - Amazon
If you click this link and make a purchase, I earn a commission at no additional cost to you.

If you enjoyed this post then please do check out my YouTube channel.

I have been Monty. This is Sportive Cyclist, the MAMIL channel. And my Garmin Varia can sense you creeping up behind me.

Safe cycling. Wink.

Monty - Sportive Cyclist
Monty is an enthusiastic road cyclist with only moderate talent. He started Sportive Cyclist in 2013 to record the journey to his first 100 mile ride, the RideLondon 100. Over time the blog has expanded to include training advice, gear reviews and road cycling tales, all from the perspective of a not-very-fit MAMIL. Since you're here, Monty would also like you to check out his YouTube channel. Also, Monty really needs to stop referring to himself in the third person.

2 thoughts on “Garmin Varia RTL515 Radar Review (And Why I Won’t Now Ride Without One)”

  1. hello: Thank you for your detailed and helpful review. I purchased the new varia RTL515 and paired it with my edge 830. Unfortunately it does not work as described. It only detects cars, no bikes or motorcycles and the edge 830 does not beep. I checked all the settings on the edge and still it does not beep and does not detect buses that are behind me. The problem that it does not detect could be as you suggested that the riders behind me were not faster than me.
    Any help regarding the beeps would be much appreciated
    Thank you again

    • Hi Joshua – with regard to the audible beeps, I think the two places to check are:

      1. Menu > System > ‘Tones’ – make sure the toggle is set to on (green)

      2. In the sensors section (swipe down from the top of the screen, select ‘Sensors’) navigate to your Radar sensor > Sensor details > Alert settings > Tones – I have mine set as ‘Multi Tone’.

      In terms of not recognising other road users, I am not sure what to say there. Is it worth checking that the Varia has a clean line of ‘vision’ behind you and is not impeded by the rear wheel, fender/mudguard, and is level (i.e. is facing horizontally).

      Hope that helps.


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