Backtracker by iKubu - Dragon Innovation

It might be useful in places where cars are rare and where there is a large difference in speed between you and the car.

It's likely it won't be able to distinguish between a car that is passing safely and one that's about to run you over. In a city, you are going to be passed all the time. It seems that you'd still need a mirror (or look behind you) to be able to really know what is going on.

There is another recent thread somewhere where this was universally panned.

This one? https://www.bikeforums.net/commuting/...seful-not.html

On almost every ride, in my mirror I see a car on a collision course in my lane, closing fast. Then they move over the center line maybe 2 or 3 seconds before they would have hit me. I don't see how this radar would help.

Not really. That perfectly describes my route, I can ride minutes between cars approaching.

I can also hear them coming almost a mile away. This is a nearly completely useless product, it's a solution in desperate search for a problem. Buy a mirror, it gives you much more information for a fraction of the cost and doesn't need to be charged.

This. The truck that hit me was in sight for almost 3/4 mile and it was too late to do anything by the time it was apparent that I was about to get hit.

I was being generous. I was thinking about more than "minutes". You'd likely need a mirror anyway (as I said). And the mirror might be enough.

Once you get to the point where there is no traffic noise where you're riding, it doesn't matter if it's minutes or hours, you can hear a car coming long before they get close to you.

Well...I wouldn't go quite that far. Depends on some things. The vehicle for one; hybrid vehicles can be almost silent. Also going downhill vehicles tend to be quieter. Trucks and motorcycles, you can hear coming a quarter mile away.

Then there's the wind-in-your-ears factor to consider. When I'm going down a long hill at speed the wind is muffling the sound to my ears so much that I can't even hear my phone/GPS prompts when they go off. It's so bad that now when I know I'm about to make a turn off a fast hill I will leave my screen on to make sure I get the visual info.

I think the product shows promise. If an app is developed to work with a BT enabled phone I might be interested in owning one ( if not too expensive ). Then again I might rather just have the BT enabled sensor alone rather than an integrated sensor/tail-light. If an app is developed I want it to integrate with other apps that might be is use at the same time.

Even pure electrics going 50+ MPH make plenty of noise, in fact I don't think they're significantly quieter than a gas powered car.

I can hear cars at least a half a mile before they get to me even when I'm going down a hill at close to 30 MPH.

There are many situations where you won't hear a car "long before" even without traffic.

Yes. A lot (most?) of the noise produced by cars is from the tires. Hybrids are quiet at low speeds (when they aren't using their ICE).

When I ride rarely does a vehicle sneak up on me without me knowing but when on more quieter back roads I tend to go into sight-seeing mode. When this happens I'm more distracted. Having a mirror helps immensely but without a mirror sometimes a car will catch me unaware. Usually this is not a big problem as most motorist will toot their horn if you are too far out into the road. Also keep in mind that after a vehicle has passed you they will still create noise. This noise helps mask the sound of approaching vehicles ( *noise produced by vehicles passing on the opposite side of the road has the same effect ). With noise all around you it becomes necessary to know which direction the noise is coming from. With that said I'm curious to know how the radar device reacts to vehicles going the opposite direction. So far no one has mentioned that. If cars passing the opposite way cause the device to light-up I really wouldn't want one.

Though mirrors can be bothersome sometimes I'm glad to have one. I'm still experimenting with head mounted mirrors and as such I feel I haven't found the perfect solution. This radar thing is interesting but I don't really know how useful it could be without actual using one. One thing I do know, there are times when I need to know "how far" approaching traffic is behind me. If out of range the radar thing isn't really going to give me the advance warning that I might want.