Originally Posted by
JohnJ80
You need at least 100 lumens in a taillight and you need at least 500 lumens in a headlight to have solid daytime visibility.
That's not true.
100lm is extremely brigt at day, so it'll blind following traffic.
Also 500lm is double the output a normal headlight has.
Even 40lm of red light is so bright, you'll blind people at a distance of 4m.
(Knog Blinder MOB Mr Chips V)
What is important for daylight visibility is a wide beam angle for the taillight.
And a steady or pulse/low frequent light mode.