Originally Posted by
bored117
I realized that what I thought was sufficient (250 lumen Cygolite) wasn't yesterday when I had to go to someplace I've never ridden before. It was okay at about 15mph. Around 20mph+, I had barely any reaction time for pot holes, etc. I would imagine I would need somewhere around 350+ for less tense of ride.
I have about the same threshold - my current light is rated at just under 400, and it is sufficient for most of my riding up to about 22-23 mph. However, If I was riding on rougher terrain, I'd opt for 800-1000 lumens.