Garmin RearVue 820 Radar Light impressions

[stompandgo]

Last week, the shop received the new Garmin RearVue 820 rear radar/light unit. I have the original, 1st generation RTL510 unit, which has been falsing a lot due to the radar band it uses interfering with modern vehicle collision detection/emergency braking/object avoidance systems. When it falses, it puts up a black overload/error screen that will not go away unless I take my hands off the bars and touch the screen. So I decided to upgrade to the RV820, which is paired to my Edge 840 computer, which I have had for a year or so. This unit also uses the standard Garmin 1/4 turn mount as it's predecessors, so that it is compatible with my custom Garmin mount on the Pinarello.

I have yet to ride with it. Tomorrow and Wednesday look great right now, so maybe then. The biggest feature upgrades are:

Longer battery life - 24+ hours
Longer range - up to 200m
Brighter light - up to 100lm
Threat size detection - bikes show up as the smallest icon, then cars, then trucks
Multiple lane detection and movement - if a vehicle is in an outside lane and is crossing over to the lane next to you, the icon follows this
Threat level detection - colors change from white to yellow to red
Multiple flash types, including a custom flash capability
On-board accelerometer detects braking and changes the flash to a steady bright brake light
It uses two new radar broadcast bands to reduce falsing

It is compatible with all computers that support the Varia, but some of the new features will only be available on more modern computers. It is also supported by a phone app, which can be used for configuration as well as display without a computer. There is a vibration button as well, so that your phone could be inside a pocket and you would get alerts via sound and vibration without the display.

I will post my impressions as I ride with it during the season. This will not be a DC Rainmaker review. You can find that on your own. Just my impressions as an early radar light adopter and someone who refuses to ride on the road without one.

 

[fooferdoggie]

that does sound cool. though I wonder of my 1030+ is up to it? or my karoo 2? doubtful.

 

[stompandgo]

that does sound cool. though I wonder of my 1030+ is up to it? or my karoo 2? doubtful.

No, only the Garmin x40/x50 computers with the latest (February) firmware support the new features. Your 1030 will work, but the features will be like all previous Varia models.

 

[6zfshdb]

Last week, the shop received the new Garmin RearVue 820 rear radar/light unit. I have the original, 1st generation RTL510 unit, which has been falsing a lot due to the radar band it uses interfering with modern vehicle collision detection/emergency braking/object avoidance systems. When it falses, it puts up a black overload/error screen that will not go away unless I take my hands off the bars and touch the screen. So I decided to upgrade to the RV820, which is paired to my Edge 840 computer, which I have had for a year or so. This unit also uses the standard Garmin 1/4 turn mount as it's predecessors, so that it is compatible with my custom Garmin mount on the Pinarello.

I have yet to ride with it. Tomorrow and Wednesday look great right now, so maybe then. The biggest feature upgrades are:

Longer battery life - 24+ hours
Longer range - up to 200m
Brighter light - up to 100lm
Threat size detection - bikes show up as the smallest icon, then cars, then trucks
Multiple lane detection and movement - if a vehicle is in an outside lane and is crossing over to the lane next to you, the icon follows this
Threat level detection - colors change from white to yellow to red
Multiple flash types, including a custom flash capability
On-board accelerometer detects braking and changes the flash to a steady bright brake light
It uses two new radar broadcast bands to reduce falsing

It is compatible with all computers that support the Varia, but some of the new features will only be available on more modern computers. It is also supported by a phone app, which can be used for configuration as well as display without a computer. There is a vibration button as well, so that your phone could be inside a pocket and you would get alerts via sound and vibration without the display.

I will post my impressions as I ride with it during the season. This will not be a DC Rainmaker review. You can find that on your own. Just my impressions as an early radar light adopter and someone who refuses to ride on the road without one.

View attachment 207622

I appreciate your ongoing review.
I'm considering the RV820, maybe you could answer a few questions I have. Web searches have not revealed many specific answers and hopefully, you could help.

1 - Can the light function be controlled from the unit itself, or does that have to be done via a paired device? Can it be turned off completely for radar use only?

2 - I'm told the Varia app has to be running in the foreground of a smartphone for the 820 to display warnings. I've read a few complaints about screen burn in from extended use. This also shortens battery life and limits what else can be displayed on the smartphone. Is this really a problem?

3 - When paired with a bike computer, Edge or similar, is the screen dedicated to the radar display or can it display other data simultaneously?

4 - Same question as #3 when the 820 is paired with a compatible smartwatch.

5 - How does the 820 Ant+ connection work with other Garmin GPS receivers (not bike computers) and what does the display look like?

I realize you may not have the necessary equipment to answer all these questions but any insight would be appreciated.

 

[stompandgo]

I appreciate your ongoing review.
I'm considering the RV820, maybe you could answer a few questions I have. Web searches have not revealed many specific answers and hopefully, you could help.

This is a great list of questions. I will do my best to answer them.

1 - Can the light function be controlled from the unit itself, or does that have to be done via a paired device? Can it be turned off completely for radar use only?

Yes, for the most part. There are five main light modes: Solid, Peloton, Night Flash, Day Flash, Off (radar use only). You can switch between them by using the button on the light, just like the other Varia units. To create the Custom flash mode, you will need the Varia app, paired to the light. The computer settings on my Garmin 840 only affect what is displayed on the screen and tones, not light modes. I cannot speak for other computers.

2 - I'm told the Varia app has to be running in the foreground of a smartphone for the 820 to display warnings. I've read a few complaints about screen burn in from extended use. This also shortens battery life and limits what else can be displayed on the smartphone. Is this really a problem?

Burn-in on phone screens depends on what kind of display the phone uses. OLED can burn in. I do not know the answer to your foreground question, but I will test it using my Samsung S25+.

3 - When paired with a bike computer, Edge or similar, is the screen dedicated to the radar display or can it display other data simultaneously?

Again, the capabilities are dependent on the computer. My Edge 840 has the ability to use all of the new features. If your computer does not have that capability, the display will be similar to all previous Varia lights. There is a display on either the left or right side (you choose) of the screen you are in (data, map, etc.) that overlays the screen view partially whenever a vehicle is detected. You can still see whatever you were displaying before the alert is triggered. The x40/50 Edge devices can display a small (one column) or large (two column) display. The Edge 1040/1050 can display half screen or full screen.

4 - Same question as #3 when the 820 is paired with a compatible smartwatch.

I own a Samsung S25+ Android phone and a Samsung Galaxy Watch 4 smartwatch. I do not know if there is a Varia app for my watch. I will check. That is all that I am able to test.

5 - How does the 820 Ant+ connection work with other Garmin GPS receivers (not bike computers) and what does the display look like?

All of the advanced display features are communicated via Bluetooth, not ANT+. The basic functions can be communicated via either. I do not own a Garmin GPS receiver with ANT+, so I cannot test it. You can always send me yours, and I'll give it a try.

Here is an example from the manual that shows what the advanced features look like on a compatible x40/x50 Garmin computer:

The first two vehicles are trucks, and the third one is a car. Orange is the trigger threat color, which switches to red as the threat increases, and then green after they pass you.

I realize you may not have the necessary equipment to answer all these questions but any insight would be appreciated.

 

[twy]

I use an RTL515 which I display on my Specialized Tero TCD. I occassionally get an error but it goes away on its own with out any intervention on my part. I never knew what caused it so this was very useful information to me as I am assuming it is the interference mentioned.

Does anyone have experience with this radar and how it displays on the Specialized TCD. I assume it is a function of the TCD and there would be no change (colored dots based on speed) but the vehicle size and brake light might be worth the upgrade.

I am also curious how well the "same speed" capability works.

 

[stompandgo]

I rode the Varia for the first time today. My ride included several roads that had traffic on them, as well as intersections. The RearVue 820 had no falses. It has longer range than the RTL510 it replaced. I would get an alert and not see the vehicle in my rear view mirror until a few seconds later. At intersections with a travel lane and a left turn lane, it showed both lanes with vehicles in them. Trucks were larger than cars. I got passed by a Sur-Ron on the trail and it showed up as a bike. I could not check the braking function, I would need help from someone with that. I did not install the Varia app on my phone. Next time. I did check for a Varia app on my Galaxy Smartwatch, no dice.

 

[edobici_forza]

Here are my thoughts on the new Varia Rearvue 820...is good, but not great. I have about 4 long rides with it so far. Two of those rides had another cyclist riding with me.

I have used the Garmin Varia RTL 515 for about 3 years, with a Garmin Edge 530, Edge 1030 and Wahoo Bolt 1.


The good:

The position of approaching vehicles, relative to my position, is useful for roads that have separate right turn lanes, where bike lane stays straight, so you have cars passing on both sides. this is common on Bay Area highway on ramps.

The new half screen: multi-lane radar/data fields. I use a Garmin 1040. not supported on older devices.

Increased battery life is always good

Higher light output
A brighter Flash: 100lm… it peaks at 100 lumens (vs 65 lumens on the RTL515)
Steady/solid Mode: Increased to 25 lumens, 5 higher than RTL515

Custom light sequence is interesting option. I created a couple and not liking what I created
in my quick tests, over the existing light options.

Built in/easy to use tether mount



The not great:

Data overload. with the extended range, I can have a dozen white blurry blocks at the bottom of the Garmin 1040 screen. It is visually confusing. There should be a toggle to remove the non-identified vehicles from the lower third of the radar screen.

The same speed radar tracking is inconsistent. When a cyclist is following me their icon is anchored just below the top dot represening me = A dot with a wide tail. The thing is, that bike could be right on my wheel or almost three bike lengths back.

Sometimes a bike can move from directly behind, to off to the side, and slightly overlapping one wheel. then the 820 sends high threat tones and displays car sized icon (not bike). It can be chaotic. I have read how group rides make the RV820 can a challenge to use. I don’t do group rides, but I can see how this could be true.

Lacks the ability to connect via ANT+ which is required to use widget from mybiketraffic to have vehicle speed and count data fields or record the ride. There is some elaborate work around using various other devices to force it into ANT+ mode, but then you loose all the positional vehicle and size information.



Thought on the new interface graphics

The new vehicle representation needs refinement. The ISO Yellow Warning Triangle over the vehicle icon is not useful. It is so tiny..it should be removed. The color coding for each icon is more important to convey threat level and should have more contrast than a faded circle overlapped by the white icon. A color block above each white icon would be much more noticeable.

I use an out-front mount for my 1040. so it is easy to see, but you only glance at if for less than a second when riding at speed. So all of the fine detailed icons are lost for real-world use.

An option to use the standard white dots for all vehicle (maybe two for a large truck) from the RTL515 generation, would seem like a simple update. I would choose this over the current variety of icons: fuzzy blobs, small line for bikes, medium block for cars, large block for large trucks - each with a glowing underneath which is not very noticeable.


USB-C

I have a few blinky lights, and other electronics, which have micro-USB, so while the USB-C of the 820, is welcome, it was never a deal breaker for me.


New Mount

I have seat rail mounts on two bikes so am not using the new seat post mount.

 

[fooferdoggie]

good info. wont be changing over since I would need a new computer too. but going use would be nice I am sick of flipping over the cable on devices. now almost nothing I now is not usb c

 

[6zfshdb]

Thanks for the info.
I took advantage of a recent Garmin sale and bought both the Rearview 820 and a Fenix 8 Pro smartwatch. I paired the 820 with my iPhone 14 using the Varia app and the Fenix watch. Haven't tested them yet since I've been too busy with home projects. It will probably be June before I hit the trail.