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
Any mirror is …better than none at all requiring a head and shoulder turn and complete loss of forward vision…
Besides just offensively monitoring the upcoming traffic, a mirror can save split seconds when you have to defensively avoid unexpected obstacles and evade approaching traffic, while still maintaining near-continuous forward vision.
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.”