Hello! thank you for having me on this forum.
I came to this forum to learn as much as possible about biking and because I have never been satisfied with the lights in all price ranges. I would like to share my opinion regarding the rear bicycle lights.
My wife and I ride 100 to 200 miles on the streets every week and our only fear is getting hit from the rear when we ride at night. My opinion is that most bikers feel safe because they have rear lights and they don't realize how invisible they are to the vehicles behind them because when I am in a vehicle I come across many bikers with rear lights that are very difficult to see at as little as 200 feet.
I have purchased some of the very expensive rear light systems and they appeared to be more than adequate when testing them 3 feet from my face, but when vehicles with dirty windshields are coming from behind at 50+ miles per hour even the most expensive rear lights are very small and almost invisible dots at 500 feet. At 500 feet and 50 mph it can be too late for the driver to make the necessary corrections to avoid hitting either your bike, or oncoming traffic.
Regardless of the number of lumens I think the small size of the light lens makes all the lights dangerous and I made my own rear light system that gets many compliments. While my lights may appear to be unprofessional for a pro biker the important fact is my bike can be seen very clearly by fast-moving vehicles at 1500+ feet.
To make my rear light I purchased a trailer light at an auto parts store for $7. This is the tail and turn signal light that has two bolts. I purchased two 100 lumen 7 LED helmet lights at Home Depot for $13 each. I removed the light bulb from the tail light, removed the white plastic lens from the bottom of the tail light, and attached the two 100 lumen lights to the existing bracket. Then, I mounted the light to the back side of a tote bag on my rear bike rack. The lens on my rear light is as large as the light on a car and just as bright.
For even more visibility, my wife puts the helmet strap around her waste. On the strap I attach 2 red blinking lights in the middle and one of the white blinking Home Depot helmet light on each side of the red lights. With these lights and the large tail light my wife can be seen from more than 3/4 of a mile. I always wear a backpack and I mounted two large reflectors, two white blinking lights, and two red blinking lights to the back of my backpack plus I have the large tail light.
We put two inexpensive front lights on each handle bar. What I like about my system is the total cost is less than $150 and should any piece break, or get lost I am not out of a large amount of cash. I don't have to worry about people stealing expensive lights. I use only AAA batteries, they are cheap, last about 10 hours, and I don't have to deal with a heavy battery nor charging system.
My trailer headlight doesn't look great for a pro rider, but I think safety is much more important than looks. I would like to see a light manufacturer make lights with a lens at least 4 inches in diameter and they could incorporate the lens to fit flush on the black tote bags that fit on top of the rear racks.
I believe a 4 inch diameter lens with 200 lumens is better than the small lenses that are available with 1500 lumens.