Originally Posted by
msdumo
I am very tech savvy but why spend a lot of money (>$250) and have a device that relies on battery life, electronics and sensors to warn you of a dangerous situation when an inexpensive mirror with your focused attention would probably give you better results. Technology is great but it is not the answer to everything.
The problem with fixed mirrors is vibration. While some are better than others at reducing vibration, the problem is always there. The problem I found with helmet and eye glass mirrors (I've used them both) is rider position. They're great at seeing what's approaching behind you if you never turn your head or change position. Every mirror I've tried have two major flaws; limited viewing area and depth of field.
I'm 74, have limited mobility, and ride on the roads a lot. I do several charity rides each year and an annual cross state ride that use busy highways. I also use my aerobars, pretty often, on long rides to take pressure off my shoulders. The biggest problem with helmet and eye glass mirrors is that they become totally useless when riding in the drops or on aerobars since your head position, and the view behind you, is completely changed. Bar end mirrors on a road bike don't change your view if you change from riding the hoods to riding the drops but can become obstructed by your arm when riding on aerobars.
My wife gave me a Varia Radar for a birthday present shortly before my last cross state ride. Until you use one, you don't know just how much of a game changer they are. I have Sprintech bar end mirrors on both my road bikes that have become a backup to my radar. The radar will detect and alert you of approaching vehicles at 153 yards (one and a half football fields) away; farther than you can see with any mirror. it also tells you how many cars are approaching and their relative distance behind you. You can also gauge the speed at which they are approaching and when they approach at very high speeds, you are warned by both visual and audio alerts. Since having the radar, other than an occasional glance, I seldom use my mirror unless I'm on a multilane road and I need to know what lane the approaching car(s) are in. The radar frees me from having to concentrate less on what's behind me and more on what's around me. If the cost of a good cycling kit and that kind of safety warning requires me charging it, I'll do it every day.