Originally Posted by gregjones

… I'm NOT going to put one [mirror] on my sunglasses, I don't wear a helmet and don't really have anywhere on the bars on my commuter that one wouldn't be in the way.

I can't see having the time to do anything about a car hitting me from behind with a 40 mph+ closing speed and I've never wrecked glancing behind me to check traffic in a car, big truck, motorcycle at twice speed limit or a bike.

Even if I had a mirror I still believe that I would "check my blind spot".

Originally Posted by gregjones

I have driven vehicles ranging from motorcycles, sports cars, station wagons and several million miles worth of big trucks. Every last one of them has had a blind spot. It is a fool that make a maneuver trusting only his mirrors…

I don't use a mirror on a bike because I'm gonna turn and look anyway. There's no way that I would trust a mirror to move myself and bike into what at a minimum would be 10 to 15 times bigger than me and moving two to five time faster. I'll look.

Use a mirror if you care.

Originally Posted by Jim from Boston

IMO, the use of a mirror is a matter of choice, but I dispute the categorical assertion that it is foolish to make a maneuver trusting only a mirror.

As I mentioned above, as a conscientious cyclist who wears right and left eyeglass mirrors I regularly though not excessively monitor the traffic behind me and I’m usually aware of the situation, including my usual blind spot with the mirror. I determine that blind spot to be about, say 8 feet wide and about 20 feet long, to my immediate left and behind.

Just this morning on a quiet road, I did a head and shoulder turn to assess this area. Even using my peripheral vision, which is less sensitive than direct vision, I had to turn significantly to completely visualize this area, taking my forward vision totally away for a brief period. Furthermore, it seems to me that perhaps the act of twisting my upper body may slightly deviate my forward direction of travel. In my mind to turn and look, with this brief loss of forward vision and control is risky, especially if I have preemptively been checking my surroundings. I may travel at least several feet at usual speed under these circumstances while perhaps simutaneously approaching a nearby obstacle.

I think these disputes that so often arise on BF may occur because the subscribers only relate to their own cycling circumstances. I can understand why someone riding rural, lightly-traveled and perhaps well-paved roads might not feel the need for a mirror, and rely on their hearing and rearward glances. On my urban commute where auto traffic may be heavy, bike lanes narrow, and hazards frequent and sudden, my mirror is the best bet.

Even on a quiet country road though, one rearward hazard I have encountered is that when a car passes, I can never be absolutely sure that another car is not immediately behind, and briefly the road noise sounds only like one car passing. Watching in the mirror as one or two cars approach and pass makes the situation perfectly clear.

Jim’s Law of the Road: “No matter how well-paved or lightly-traveled the Road, a vehicle is likely to pass on the left as you encounter an obstacle on the right.”

Originally Posted by Jim from Boston

Also in winter, my head and neck are so swathed in neck and face wear that turning around becomes more limited, and hearing is diminished, making the mirrors even more useful.