Originally Posted by Iride01

fwiw, I've never used a mirror while cycling. I don't know why I need to know what is behind me since my mass and velocity aren't likely to kill anyone else passing me. Especially if they are in a car or truck. I also expect that any behind me will follow the rules of the road and know that I have the ultimate privilege over anything they do until they safely complete passing me. I'm not so naive to expect that everyone passing has half a brain or even cares me or my safety. But I also realize that if I was looking in the mirror, I wouldn't be able to identify those that were going to harm me until it is way too late to do anything about it.

I have many times had unsafe situations created when those I was overtaking that had mirrors decided to act in a unexpected manner. So if you use a mirror, make sure you first and foremost just ride predictably when being overtaken. Don't slow down suddenly and force me to jam on my brakes or have to pass you when conditions are not favorable for me to pass. Just because passing might be for you doesn't mean I can see around the blind curve we are on or feel confident that I can pass you before becoming a risk myself to oncoming traffic.

Believe me, I and others are unlikely to want to draft on you any longer than it takes to make the needed traffic checks and be in a safe place to pass you. I always will tell you what I'm doing whether it's passing or having to stay behind you if you just give me a chance before brake checking me.