PromptCritical 

Prices for rear facing radar are becoming reasonable and there are a couple of brands available.

Does anyone have any experience with one?

13ollocks

I’ve used a Garmin Varia in combination with a Garmin Edge 530 head unit for the last few years. It’s been fantastic - combined with a bar-end rear view, it gives me a great picture of what’s going on behind me. I won’t say I wouldn’t ride without one, but I’d feel pretty naked

PeteHski

I’ve also been using a Garmin Varia RTL515 for a couple of years with a Garmin 530 GPS. It works great and I wouldn’t ride without it. The combined rear light is very effective too.

Iride01 

Garmin was pretty much the first out with one. I've had one for 3 or 4 years and my son had one since they came out with it. While I'd miss it if I left it at home on the charger while out for a ride, it really doesn't add anything but marginal awareness for me. I usually hear the car coming from behind just a split second before it alerts. Though occasionally on long stretches with boredom the chirp brings me out of my daydream of cycling greatness long gone! <grin>

There have been times when a car will follow me at the same speed for a time waiting for a chance to pass and it will disappear from the display. But when it begins the pass and speeds up, it shows up again. So more weight seems to be on closure speed of the objects behind.

It does sometimes help me to realize there are multiple targets behind me. But regardless, it doesn't really change any of my behavior on the road. I still glance behind me before swerving or turning.

Bald Paul

I've been running a Garmin RTC715 since they came out, in conjunction with the Edge 1030+ and a rearview mirror. I wouldn't ride without them.

howaboutme

I've been using the Bryton Gardia 300L and really like it. I think it looks sleeker than the Garmin and is certainly less expensive, especially on sale. It connects and never drops from my Wahoo computer. There are some quarks, as discussed in the many youtube videos. On occasions, if the car is behind you and following you at the same speed for a period of time, the radar may think the car is not there. I knew that going in and not a huge issue for me as the radar should complement us physically looking back and not replace that. It comes with assorted mounts ready for any seat tube.

Sierra_rider

I use the Varia RTL515 paired with an Edge 530...works well and no big complaints. I particularly like it when I'm going downhill and the wind noise makes it impossible to hear cars behind me.

veganbikes

I have a Garmin radar light and love it so far. Maybe the radar is a little less useful in an urban environment but the light is awesome and overall I have no real complaints about it my only issue is wiring the thing but that is less of a concern for most as they may not have one mounted on an-ebike and they may not have it mounted on the seat post as I do.

Eric F 

I use a Garmin Varia radar with a Wahoo Bolt head unit. It's excellent. Having an audible alert means I don't need to be looking at a mirror or my head unit to know there's a car coming.

Steve B.

I admit I'm a gadget nut, already have a 1040, could see adding a rear camera/radar/light. Not sure they do camera and radar. Not sure radar would be very useful, for one thing I am very hard of hearing and do not hear beeping from my 1040, as well tend to ride in a congested are so there are ALWAYS cars coming up behind me and I am used to riding in these traffic conditions. For the times I need to see if that matters (using the lane to pass parked cars) I have a bar end mirror. So I question whether a radar is all that useful.

Bald Paul

Garmin RTC715. Radar, light, and video camera.

Steve B.

But begs the question is a radar useful when it’s constantly triggering alerts ?.

Eric F 

The audio alert can be silenced. The graphic display is still useful. (IME, YMMV)

Iride01 

Have you checked the alert or tone setting for the Varia in the <Sensor Details> of your 1040? I didn't think it originally had a option for tones, but maybe it changed with a later update.

I too use to not be able to hear mine. Though most of my hearing is good, there are some frequencies I don't hear well.. But one day I noticed it had a mono tone and a multi tone option. Changing it to multi tone made much easier for me to hear. Even when the wind is making noise in my ears.

Bald Paul

What makes you think the radar is constantly triggering alerts? It alerts you when a vehicle is approaching at a higher rate of speed than you are riding at. Would you rather not get alerts, or only get a percentage of them? Would you like the radar to not warn of the one vehicle that is about to hit you?

Mtracer

I also have a Garmin RCT715 (camera, light, radar) and like it well enough. The only issue I had was when I tried it mounted to my saddle. The saddle movement caused distortion in the video.

The radar is a nice extra thing to have. But, I rely on a mirror much more. I.E., if I had to choose between radar and mirror, I'm taking the mirror.But of course, you can have both.

All of these radars are going to have a detection pattern that is like a cone radiating out from the radar. This means that the further back the wider the detection zone. So, for example, if you are on a frontage road, they will pickup vehicles on a parallel highway. This can cause a lot of "false" detections. False in the sense that the vehicles are not on the same road as you.

In the case of the Garmin, they do not have a way to temporarily defeat the audible alarm. For example, press a button to disable audible alarms for 1 minute or something like that. So, there can be a tendency to ignore the sound. But I think my brain has sort of learned to ignore it in those specific situations. But again, I use a mirror and as with a car rear-view mirror it takes a fleeting glance to check behind me.

For me, the radar is an extra thing for situational awareness. For someone who doesn't use a mirror, I could see how it could be their primary way of keeping track of what is behind them to avoid surprises. I would never rely on it and move out into a traffic lane. Though I have never, ever had it NOT detect anything overtaking me. Also, it really doesn't give true false detection other than inside where the radar presumably bouncing off the walls.

The Garmin radar light also flashes differently as cars overtake. So, there may be some slight improvement in safety if this change helps a driver notice me more easily. Every little bit helps.

Eric F 

When riding on a street with a lot of vehicle traffic, constant audible alerts can get pretty overwhelming. If I'm riding in those conditions, I tend to mute the audible.

howaboutme

I agree. If you are always riding on roads w/ cars, then this item is not as necessary as you should ride always assuming there's a car behind you.

Iride01 

I always assume something might be behind me. Whether in crowded traffic or no other traffic. I always think it a good idea to actually look before doing anything but what I'm currently doing.

Still, I do like to have the Varia. Maybe the beeps keep me company on my frequent solo rides!

Steve B.

I don’t own a Varia. To clarify my question, I wonder if folks who live in less urban areas and are often on backroads, often without shoulders, are finding these more useful then perhaps a rider, like myself, who rides in more congested areas, where there is pretty much always a car back, as it were. Thus a user in a congested area, might have less need for a radar, as it’s kind of telling you what you already know, there’s a car back. In a rural area, I understand the usefulness as it alerts you and gives you time to maybe move a bit out of whatever lane is remaining. As well, I really doubt I would hear an audible alert, I don’t wear my hearing aids when I ride and I currently do not hear the audible alerts a 1040 gives for navigation route changes.

The rear camera is a feature I might desire as it provides a record of “what happened” when a teenager on a cell phone mows you down. Thus my interest in plunking down $400 is increased.

SoSmellyAir

I have a Varia RTL-515, and prior to getting it, I had similar concerns as Steve B., that frequent alerts while riding in suburbia would be annoying. Now that I have had mine for a year, that has not been the case, and I would not ride without one. The Varia does not give one audio alert per approaching object. There is an audio alert when a first approaching object is detected, and additional approaching objects are shown and tracked on the display (of the Garmin iOS app or bike head unit) without additional audio alerts. It also gives an "all clear" audio signal after vehicles are no longer detected within range.

However, as noted, the initial detection is based on closing speed, and the Varia stops tracking an object after the object maintains the same speed as the radar for a while. But this has rarely caused an issue for me. Despite this shortcoming, I doubt that one can track multiple approaching vehicles as well without one.

Atlas Shrugged

Very seldom will someone purchase a Garmin Varia radar and not be extremely pleased with its performance and contribution to the riding experience. Even with a fairly old demographic that traditionally uses mirrors, they find it an excellent addition to their riding equipment. Its situational awareness transforms both an urban riding experience as well as one in the countryside. The ability to see how many cars are behind you alone improves one's awareness and safety. There is no point in trying to convince the naysayers its benefits, but rather notice how the only people who feel it is not beneficial are those who haven't used it.

howaboutme

Ok. I agree w/ you but I think you missed my point. My point is similar to the post just below yours. Of course always look behind!

PromptCritical 

Well, this is a pretty uniform positive response from actual users! Might be time to look into buying one.

Has anyone used the Trek CarBack unit?

Also, the Garmin units appear to have a short (1.5 hour) battery life. Are they capable of accepting a charge while operating?

Troul 

no issues with the Bryton. it has only detected traffic that was approaching from behind 7 the visual alert changes colors as the closest detected object closes the gap. I'm not sure if other brands are as savvy WRT detecting traffic.