Originally Posted By: Tjin
It's not about lumens. Its the beam pattern and lux.

It's the same as a high or low beam on a car. A regular flashlight is equal to a high beam. A proper bike light has a cut of to act like a low beam.

Put the bike in front of your car with the light on and sit in the car to see what the effect is.

The Germans even made a law regarding bike light needing to be a low beam; the StVZO standard. It's just the Germans that made it in to a law, but it doesn't beam blinding people else where is good.

Random google hit on StVZO: https://www.bikeradar.com/advice/buyers-guides/stvzo-bike-lights/

A regular flashlight beam battern is however fine for mountain biking; as you don't have other traffic and allows you to see branches. Although i would recommend to have a headlight and handle bar mounted one, so you can see in to the corners.


Looking at the photographs on that site, they don't bear any resemblance whatsoever to the amount of light coming out of my flashlight on the 150 lumen or 350 lumen settings, which is all that I use, and again, I will note that even the higher of those two modes is still half the lumens of an average automotive halogen lamp. The Lupine SL AX in that article is a 2200 lumen light, about 15 times the output of what I typically use. its low beam setting is 1300 lumens, and its daytime running light is 180 lumens, brighter than what I typically use at night.

My flashlight it pointed at the ground no more than 3 metres in front of my tire. In no way does it illuminate to the distances shown in those photographs. And for the record, I went to university for Lighting Design. I'm pretty sure I know what I'm doing. Thanks for the advice.

Also, one other thing. I was pretty impressed with the Nitecore BR25, which has a hood over the front that directs light downward to illuminate the bicycle itself and the ground immediately below it to make one more visible. I think this is an interesting idea, but the performance of the unit itself is not as good as my Fenix PD36 TAC. So, one of the things I'm looking at is fabricating a removable reflector hood out of black ABS and white PVC pipe fittings for my PD36 TAC do do more or less what the Nitecore BR25's non-removable hood does.


Edited by amper (11/30/21 07:19 PM)
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