Not an issue for me - I just use the mirror to let me know whether a vehicle is in the next lane over or not . I don't need to see every little detail of the vehicle.

It's just like when I drive my car in the rain. A wet mirror might make it harder for me to tell if the car on the next lane over is a Nissan or a Toyota, but I can see that there is a car, no matter how wet the mirror gets.

Not going through the whole thread, but you can see behind you without taking your eyes off of what is in front of you.
I use a glasses mounted mirror and feel naked and vulnerable without it now.

You seem to forget about all the "chain of events" that one is depending on to prevent an incident, while in a bike lane or shoulder, like depending on motorists seeing you while pulling out from a driveway or side street, when turning right, when turning left from the other direction (especially turning left right after a large vehicle passes). No thank you, I prefer to minimize those odds as much as possible, by being as visible as possible.

You do realize that you're also dependent upon those same chain of events when driving your car (or truck as I believe you do?) to prevent an incident, right?

I worry less about vehicles I can see in front of me that I can react to than those behind me (which I want to give the most space possible).

Hence why I use a mirror and have plenty of room to maneuver should I feel a car is barreling up on me too fast. I also know when a car is there so I can communicate with them appropriately if needed.

I got my hands on the Garmin Varia Radar thing this week. Very interesting addition to a ride. I found that it enabled me to be much smarter about looking behind me and I was able to spend more time watching the road in front.

J.

Weird. Does the radar start to detect a car sooner than you can hear it?

Yes, very much so. And it will track multiple cars presuming they are not hidden completely behind one another. It reaches out about 500' or about one city block. On the highway, it gives you about a 6-7 second warning of an approaching car at 60mph or so. In the city, it's much longer than that because cars are moving slower.

I was prepared to think it was kind of an gimmicky thing, but I'm really starting to like it a lot. I haven't had it give me a false negative yet (i.e. not identifying a following car when there was one) and don't think it will. I have gotten a couple of false positives (telling me there was a car there when there wasn't) but that seemed to happen on turns when there was a large metal sign down range or a car in part of the intersection as I turn through it. I don't get false positives when I'm riding down the road.

The tail light is pretty much unimpressive at 16 lumens. The idea that it starts and blinks as a car approaches is nice, but it really needs to be more in the 70-100 lumen range IMHO. I ride with some serious tail lights (high bright ones) that cause driver behavior to change. This light does not induce that behavior and I would not recommend it as the only tail light for a night ride. I also wish Garmin would add the choice to completely turn the tail light off but leave the radar on.

So I think it's an impressive product. I definitely appreciate the cue to look in the mirror or to turn around and look. I do find that I miss it if I don't have it on the bike.

J.

Haven't read the whole thread but do agree with the above. Even on a clear day, I just want to know that something (car or bike) is behind me. I don't need to identify make and model.

On a solo ride this weekend, I was noticing how I use my mirror. It only takes me about 1/2 second to slightly turn my head to aim the mirror straight back and glance back to see that the road is clear. It's more like 1 to 1 1/2 seconds to sweep from side to side, a field of view at least 90 degrees wide to the rear.

So a quick glance is fast and easy, and I don't lose track of what's going on ahead of me. I can do this way more often than I would turn my head far enough to clearly see the lane behind me. It's just about the same amount of time as using a car's side mirror.

But I still get surprised by cars passing sometimes. I don't always look back when the road isn't busy. And wind noise usually covers the sound of car tires when I'm faster than 15 mph.

If a car has slowed to wait behind me, I'll usually turn my head and fake a look back, so the driver knows that I'm aware of them.

Sometimes a driver will lag behind me out of courtesy or confusion. If the road is clear and wide I will motion to them with my hand to pass me. I wonder if they are surprised that I have acknowledged their presence without turning my head.

I ride tight streets with fast moving vehicles my mirror on the end of my drops is invaluable to me at least. Mirror I use doesn't stick out any wider than I am, I like to know when the next vehicle is going to come up next to me at 50 mph and pass less than a foot off my left. To me it's like in a car you can use the mirrors a lot quicker than turning your head each time. Of course that's just me others may and do have different opinions but we're all correct if it works for us.

I just bought a 2nd Take-A-Look mirror to leave clipped on my clear glasses. It's getting to the time of year when it's dark when I leave in the morning and light when I go home. Previously I'd just move my mirror back and forth between my clear glasses and sun glasses, but having a 2nd mirror I can just leave attached and adjusted will be much more convenient. And it was only $10. Should have bought a 2nd one a few years ago.

That's just an aside that doesn't really pertain to the OP's question of "why use a mirror." So please continue arguing...