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Garmin Varia RTL515 Review and Garmin Varia RVR315
Garmin today announced the Varia RTL515 which is a modest update on the sweet Varia RTL510 rear-facing radar-light and also the wholly new Varia RTL315 which is intriguingly just a radar unit without a light.
Garmin Varia lights are those brilliant accessories that you never knew you either needed or wanted…until you actually bought and used one.
Varia RTL515 and Varia RVR315 – What’s new?

The Garmin Varia RVR315 is a new product. More on that in a minute, for those of you looking at what’s new on the RTL515, it just seems to be this
- Peloton Mode: RTL515 offers an ANT+ only mode that provides a low-intensity light that is kind to other cyclists’ eyes.
- Improved Mounting: Varia can now be mounted to D-shaped, aero, and round seat posts.
- Optimized Battery Life: ‘Up to’ 16 hours in day flash mode, 6 in solid for RTL515, and up to 7 hours for RVR315
- BLE Support
These are small but noteworthy improvements (as they all affect me 😉 ). Whilst fellow peloton members can pair to your Varia to share in your vehicle warnings, the reality is they won’t and all your fellow cyclists will do is moan that your light is too bright…not now with PELOTON MODE.
I have a Cervelo R5 and the old mounts simply do not properly work on the D-shape cross-section of my seat post. Now they do. Although I STRONGLY recommend getting a proper seatpost bracket (or similar) rather than trusting your very expensive light to a single elastic band.
….and you get an extra hour of juice. Maybe.
BLE Support ?!? Sounds rubbish, right? Read on.
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Garmin Varia RVR315 – aka the intriguing one.
I mean…why? A radar and no light? Surely the whole point is to stop those fast-moving chunks of metal (cars, lorries) from whacking you from behind?
Well, yes. But Garmin did introduce this for a good reason, or two, although I’m not sure if the RTL315 will justify itself on these 2 grounds, in the market. Here’s a very exciting series of images of the RVR315 and the Garmin Varia Radar app that you can use with it on your smartphone.
I’ve used the RTL510 a LOT and one of its benefits is that you can glance down at your bike and see a car approaching from the rear, indicated on your Garmin Edge/Garmin Forerunner/Wahoo/Stages/Karoo bike computer. Thus it gives you a heads-up to determine if you have to perform a heads-back look back over your shoulder before moving out for some reason. OK, I get it, YES you still have to look over your shoulder but if Varia says there are 5 cars bearing down on you then you might just decide to stay where you are rather than even think about attempting a manoeuvre.
So let’s say you’ve already invested in some cheap flashing light for your own safety, then the RTL315 could be a nice little upgrade for you to complement your existing lights. The RVR315 will give you some rear-view intelligence.
I’ve not convinced myself with that argument, so I doubt I’ve convinced you either!
Garmin Varia RTL515 – Meh
Let’s say, like me, you’ve already got an RTL510. What’s the point in forking out another small fortune for a near-identical upgrade? The battery life is claimed to be a bit better. But is it $200 better? Probably not. That’s my argument for NOT buying the RTL515 as an upgrade to the RTL510.
However, as brilliant as the RTL510 is, it DOES run out of juice too easily. It is my single-most annoying product in that regard. The RTL510’s battery life in day-flash mode is supposedly 15 hours – with the new RTL515 having a claimed 16 hours. 15 hours may have been the case at launch for the 510 but I now get nowhere near that amount and I would say I’m lucky to get 10 hours. So if you couple two 4-hour rides with forgetting to turn it off after the first ride then, towards the end of that second ride, you always get the annoyingly-useful LOW RADAR BATTERY warning popping up. This is mainly a ‘user error’ caused by me not charging up the RTL as often as I do my bike computers, yet I’d say I’m generally good at keeping my things juiced-up…just not with the Varia.
Long story short….it might be worth getting the RTL515 for the extra hour of improved battery life and perhaps a brand new battery rather than one that might have been sitting in a Garmin warehouse somewhere, degrading slowly for the last 2 years 😉
However if you’re going to buy your first Varia DEFINITELY get the 515 and, maybe, if you’re contemplating upgrading then just think about the potentially better battery a little bit longer.
Garmin Varia RTL515 – Brilliant
The RTL515 now offers BLE connectivity when previously it was ANT+ only
“What the…?!?” you say. “Why is BLE brilliant?” you add.
Here’s why.
This is commercial mini-masterstroke by Garmin. The reason is that now smartphone apps can support Garmin Varia radar. So this opens up a whole new market segment for Garmin ie riders who record their rides with apps not bike computers.
Let’s face it there are quite a few ‘serious’ cyclists who don’t even wear helmets, yet I’m betting that everyone that uses a smartphone bike app to record their ride wears a helmet and are generally a safety-conscious lot. So let’s increase that safety with rear-facing radar alerts and smartly flashing lights to warn vehicles of your presence.
This partly explains the keenness of Ride With GPS (RwGPS) to get in on the act to support the RTL515 as from NOW. They have a great chance to sway over even more STRAVA app users who previously recorded their rides with STRAVA but who have gotten increasingly annoyed as STRAVA remove external sensor support. Jeez…RwGPS even supports power meters!
Fun Fact: RwGPS have never had VC funding. #Kudos
Garmin Varia on Bike Computers
My super-detailed review of the earlier Varia RTL510 is in the link that immediately follows, is a good place to see, side by side, how the implementations of Varia subtly differ from one bike computer manufacturer to another – or you could just look at the image above which is a bit quicker 😉
AFAIK none of the non-Garmin bike computer manufacturers supports the ability to use PELOTON mode, although Hammerhead said they will at least look at that shortly.
Garmin Varia on Smartphone Apps…well, RwGPS
As well as the Garmin Varia RADAR app, Garmin has partnered with RwGPS for smartphone app integrations with the new BLE-enabled Varias. Here we have some screens from RideWithGPS which shows what looks to be a generally well-thought-through implementation.
OK, some of the voluminous screen real-estate is lost to the Varia bar at the side but that would be a trivial criticism when you compare the awesomeness of how RwGPS looks on screen compared to probably any dedicated bike computer. I hate to admit it, it even looks prettier than the Hammerhead Karoo here 😉
The RwGPS sidebar for Varia even gives information on how far behind approaching cars are if you look closely.
RwGPS claim that one of the key innovations that the smartphone app platform has allowed them to make is the introduction of cleverer audio alerts including, for example, to make a special audible warning for RAPIDLY approaching cars and for when the danger has passed. #Maybe. The argument makes sense I’m sure in some scenarios, however in other scenarios with busy roads I know Varia users disable the volume to stop annoying permanent audio alerts.

More: RideWithGPS.com
Garmin Varia RTL515 & Varia RVR315 Key Specifications
The RTL specs are little changed from the RTL510. Similarly, the German version was the RTL511 and is now the RTL516 and that just has the flashing light disabled to comply with German law.
Here are the key specs
- Max Claimed Battery Life – RTL515 (16 hours), RVR315 (7 hours)
- Car Detection Distance – Claimed 140m
- Connection – USB (charging), BLE, ANT+
- Light Visibility Distance – Claimed 1500m/1 mile (RTL515)
Here are the rest for the RTL515
- Modes: solid, peloton, night flash, day flash
- Battery Life – Up to 16 hours (6 hours solid, 6 hours night flash, 16 hours day flash)
- Lumens: 20lm solid, 29lm night-flash, 65lm day-flash (Contrast to Bontrager Flare R – 65 Lumens with 2km visibility, 270-degree angle)
- Dimensions: 98.6 x 19.7 x 39.6 mm
- Weight: 71.0 g
- Visibility – 1 mile
- Side visibility – Yes
- The angle of light visibility – 220 degrees
- RADAR Angle – 40 degrees
- Charging cable – Micro USB (the 2020 version…nah just kidding, the REALLY old micro USB version)
- Communications – ANT+, BLE
- Vehicle detection – 140m/150yards
- Compatability – Garmin Edge, some Garmin Forerunner, Hammerhead Karoo, Stages Dash, Wahoo ELEMNT (check thisisant.com), some smartphone apps eg RwGPS
- Water rating: IPX7
- RADAR detects 8 vehicles
- Approach speed detection – 10 to 160 km/h (from 6 to 99 mph)
- Manual: here when available
- Latest Firmware used: TBC (firmware notes and history HERE WHEN AVAILABLE)
- Alternative mounts eg saddle/saddle-bag mounts: Check SHAPEWAYS.com
Thoughts & Opinions
Jeez, these are expensive. I mean really expensive. Is your life or your partners worth Eu200?
Err. Wait a minute. Maybe 😉 It’s probably the same price as a few years of life insurance.
- If you have an RTL510 then don’t upgrade unless you haven’t bought anything for your bike for a while.
- If you have a compatible smartphone app then go for it
- If you’ve already got smart lights then think about the radar-only model
- The Forerunner 945 (or any other supported watch) works reasonably well. I have mine set up and mainly use its audio alerts when working with a karoo that has no sound. if you have your watch on the handlebar that would work ok too but on your wrist, the visual alert is not so easy (and safe) to use. See the image further above
- The Wahoo BOLT gets frequent dropouts to Varia (RADAR Disconnected), which is a PITA. Say, once or twice an hour.
- See comments below that RADAR-only usage is not possible with the RTL515
RTL515 Pricing & Availability
Pricing is a little on the high side. On a positive note, these high prices will enable deeper discounting on the earlier RTL510, at least until stocks run out.
- RTL515 – Eu199
- RVR315 – Eu149
The following links to all Varia products sold at key retailers. The RTL515 should appear once the retailers correctly list it.