Cars following losing white dot

That's how it's meant to work, it only brightens and flashes if the car behind is gaining on you. From the overview on the web page:

•Tail light unit brightens and flashes to notify approaching traffic of a cyclist ahead (underlining is mine)

That's how it's meant to work, it only brightens and flashes if the car behind is gaining on you. From the overview on the web page:

•Tail light unit brightens and flashes to notify approaching traffic of a cyclist ahead (underlining is mine)

My point is that the unit continues to be bright and flash when the car is following. It must then know the car is still behind so therefore why is the White Dot not still displayed on the 1000.
I bought the Varia BOTH for the flashing light warning cars of me BUT mainly for the display on the 1000 showing cars behind.

On your earlier post you were going to have a ride with a Varia, have you managed this yet? What is your feedback?

So, I took my first ride with the Varia tailight today. Overall, I'd say I'm pretty happy with it. Here are my initial observations with it. It was consistently good about picking up vehicles approaching me from behind me, well before I could hear them coming. I had a few false alerts. Interestingly though all of them were when I was on a bike path separated from a road, not on a road with traffic itself. I'm not sure what caused them, but they were brief before going away. One time may have been a plastic bag flying around in the air. It was windy and gusty today and I saw the bag tumbling in the air as I rode past it and then briefly saw a dot on my Edge before it disappeared. It also picked up cars approaching from behind that were on a road next to me, but we were separated by a concrete barrier. So there are some false alerts so far, but it's something that can be calibrated with updates over time I would think. In the end, I will take a few false alerts over the system eliminating something that really is a car approaching.

The gap from the bottom of the screen to the top does seem to truly represent distance. I noticed a couple times when I went through an intersection and a car turned right onto the road behind me, the Varia would pick up the car, but the white dot would already be very close to the top. Which makes sense given the real life proximity.

The only way to really know how the flashing is working and what could possibly being cause false alarms or cars to disappear would be to mount 1 camera facing rearward to see what the Varia is seeing, and 1 at the Varia itself to see how the flashing changes and review the videos synced together. Any volunteers? :D

Is the Varia the end all be all for being aware of cars approaching from behind? No. But having a blind spot monitoring system for your car doesn't eliminate the need for mirrors or the need for you to turn your head and look before changing lanes. I work in the car industry and I've seen plenty of cars with rear end damage from backing up, despite having parking sensors AND a rear view camera. Safety technology for a car or bike can be used to improve safety but cannot be relied on exclusively So far, technology is not a replacement for caution, common sense and luck. I think the Varia is a great complement to situational awareness and a mirror. A biking mirror can and does have blind spots just like a car mirror. The Varia adds another layer of safety I think. I add more thoughts as I continue to use the Varia. So far, I'm pretty happy with it.

I agree that the Varia's doing what it's meant to be doing, but I also agree that still showing a vehicle once it's matching speed behind you would be a very useful feature if it could be made available. I don't think anyone's suggesting that the Varia doesn't replace the need for a visible check behind, but it can complement that and by doing so increase safety. Personally, I do most of my riding down country roads, and every so often I'll get a car behind me that just doesn't seem to want to overtake, even when there's a sufficient straight, which can be a bit unnerving as I find myself thinking "is it still there, has it turned off" etc. I end up regularly glancing round which isn't always ideal on pot-holed country lanes - having the white dot stay on my Edge would be great for me under those circumstances.

I've not had chance to try yet, but I would have also thought there would be a danger of a vehicle pulling out of a junction behind you not registering if it matched speed with you as it came out of the junction, or even round a bend.

YMMV

Just a thought for those of you worried about the dot dissappearing, how does the Varia behave if you're cycling in a group, you could have a dot on the screen for the whole of the ride. :confused:

Just a thought for those of you worried about the dot dissappearing, how does the Varia behave if you're cycling in a group, you could have a dot on the screen for the whole of the ride. :confused:

My understanding is that it's smart enough to filter out cycles

My understanding is that it's smart enough to filter out cycles

In the same way it filters vehicles travelling at the same speed as you? ;)

I don't have an issue with a car behind me. My issue is that the Varia display shows cars approaching but then stops displaying them when they are travelling behind. What I am saying is the dot should continue to be displayed when a car is following and drop off when the car passes. If you don't agree please explain why it's right to stop displaying the dot.

Richard

What else could the unit do? It has to be coded so that targets are removed what is the difference between a vehicle passing and one that is travelling with you from the point of view of the unit? I certainly wouldn't want the unit active in heavy traffic it would be next to useless on a city road. The whole point is it warns you of an object that is approaching at a threat speed where it is possible you haven't been seen.

Once the vehicle is traveling at your speed (or perhaps +5 mph) one could reasonably assume the rider has been seen and therefore isn't a threat in the same way.

I agree that the Varia's doing what it's meant to be doing, but I also agree that still showing a vehicle once it's matching speed behind you would be a very useful feature if it could be made available. I don't think anyone's suggesting that the Varia doesn't replace the need for a visible check behind, but it can complement that and by doing so increase safety. Personally, I do most of my riding down country roads, and every so often I'll get a car behind me that just doesn't seem to want to overtake, even when there's a sufficient straight, which can be a bit unnerving as I find myself thinking "is it still there, has it turned off" etc. I end up regularly glancing round which isn't always ideal on pot-holed country lanes - having the white dot stay on my Edge would be great for me under those circumstances.

I've not had chance to try yet, but I would have also thought there would be a danger of a vehicle pulling out of a junction behind you not registering if it matched speed with you as it came out of the junction, or even round a bend.

YMMV

Don't get me wrong, I'm in complete agreement with you. While I like what it does, I would love it to show a vehicle matching its speed behind me. That would make it more complete. I absolutely agree there, it's just that that it would require a lot more complex tech. Think of the Varia as something similar to a police officer's radar gun, rather than the radar that an air traffic controller uses. The radar gun only give readings when an object is moving away or towards it. It will not tell the officer specifically which vehicle it is, but by pointing specifically at a certain vehicle, the officer can be pretty sure which one it is. However, if the officer were to try to use the radar gun from his moving police car at a car in front of him moving at the same speed, guess what speed it will show? Zero. What if the car was going 5 mph faster? 5 mph. The car mounted radar guns have info on how fast the patrol car is going so that it can calculate and give a speed for the car being tracked. I have a feeling that the Varia has some sort of threshold such as 5 mph which was discussed earlier before reporting a dot to help filter out false alarms. So, maybe if the Varia had two way communication with the Edge computer and knew when say, it said you were going at least 5 mph, they could get rid of the 5 mph threshold on the Varia and let it report anything that was behind you, even a "static" object. Then it might be able successfully show a car that has slowed down and started pacing you. The knowing that you are moving would be critical I would think to keep if from reporting every single object behind you, moving or not. That way static objects would be moving away from you as you pedaled and would be treated like cars moving past you. I don't know if the Varia is transmit only or can receive data. If it can, the solution could be a firmware fix away. Otherwise, we may have to wait for the next evolution.

In the same way it filters vehicles travelling at the same speed as you? ;)

No, I think it has something to do with the size of the object. I've had a two cyclists side-by-side approach and pass me from behind while I was just coasting and they didn't register. Of course that's just one isolated case though so it doesn't prove anything, and I appreciate a peloton might be a different story.

Don't get me wrong, I'm in complete agreement with you. While I like what it does, I would love it to show a vehicle matching its speed behind me. That would make it more complete. I absolutely agree there, it's just that that it would require a lot more complex tech. Think of the Varia as something similar to a police officer's radar gun, rather than the radar that an air traffic controller uses. The radar gun only give readings when an object is moving away or towards it. It will not tell the officer specifically which vehicle it is, but by pointing specifically at a certain vehicle, the officer can be pretty sure which one it is. However, if the officer were to try to use the radar gun from his moving police car at a car in front of him moving at the same speed, guess what speed it will show? Zero. What if the car was going 5 mph faster? 5 mph. The car mounted radar guns have info on how fast the patrol car is going so that it can calculate and give a speed for the car being tracked. I have a feeling that the Varia has some sort of threshold such as 5 mph which was discussed earlier before reporting a dot to help filter out false alarms. So, maybe if the Varia had two way communication with the Edge computer and knew when say, it said you were going at least 5 mph, they could get rid of the 5 mph threshold on the Varia and let it report anything that was behind you, even a "static" object. Then it might be able successfully show a car that has slowed down and started pacing you. The knowing that you are moving would be critical I would think to keep if from reporting every single object behind you, moving or not. That way static objects would be moving away from you as you pedaled and would be treated like cars moving past you. I don't know if the Varia is transmit only or can receive data. If it can, the solution could be a firmware fix away. Otherwise, we may have to wait for the next evolution.

Yes and no - I agree that the Varia probably uses a simple doppler radar like a speed gun, but for this very reason it should be very simple for it to register vehicles moving the same speed as you. In fact, it will already be doing this, just not showing them on the display. In simple terms, the doppler shift of the returning signal will show that an object is either moving closer (the amount of shift will indicate by what speed relative to the radar/bike), moving away (again, speed indicated by doppler shift), or stationary relative to the the radar/bike. So, to keep it simple, let's say you're travelling at 25km/h with a car approaching you at 40km/h. The Varia will register a differential of -25km/h with the trees/road/houses and a differential of +15km/h with the car. As the car slows down behind you and matches your speed, the differential will drop to 0km/h. Remember, that the radar still sees the car, and the "0" doppler shift is no different in how it registers with it than a + or - value. Imagine I play you a note on a keyboard; I can adjust the tone to make the note higher or lower, but even with no adjustment you still hear the note. So I'd assume that at the moment, the Edge (or whatever headend that's being used) is programmed to only display object with a positive relative speed of something like 5km/h (that's just my guess at what threshold they could have used). All they would need to do would be to reduce that threshold to 0km/h (or maybe a little less) to keep vehicles trailing you still showing on the display. The key thing is it's all about speeds relative to the bike/varia and the car - the actual speed you're travelling is irrelevant.