Urban areas, dark roads, e-bike or off-road use? The answer will depend on the use and the area where you usually go biking.
If you ride in well-lit urban areas, a common recommendation is at least 100 lumens or more to both see and be seen. Good options from Herrmans range: MR4, MR5, MR8.
With that said, any light is always better than no light. Already with a light of say 40 lumens you will be safer and more visible in traffic than without any light at all. But to see well in an urban setting, then 100 lm is a good starting point.
If you ride on dark roads with no other illumination, 200 Lumens or more is advisable. Suggestions from Herrmans range: MR9, H-Black Pro. Also keep an eye out for Nordic MR10 or MR10+ with high beam that will be released next in the Nordic range!
Your speed is another important factor. If you ride a fast road bike or use an e-bike where you travel up to 25 or even 45 km/hour, you might want even more light and visibility for your safety. Or maybe you just feel more at ease riding at night with a strong light, to really see your surroundings well.
Whatever the reason you prefer a stronger light, Herrmans’ Nordic Pro is a smart choice (650 lm/120 lx). Or its big brother Nordic Xtreme; a solid companion on any ride with the included high-beam function (1100 lm/250 lx). Both have very generous light patterns.
In dark off-road terrain we recommend 500 lumen or more. The most light will be needed when riding MTB out in the forest or mountain terrain in the dark. Then you want to have a broad light pattern, which means you don’t necessarily need more lux, but more lumens to be able to get a broader light image. Our flagships Nordic Pro and Xtreme with their wide light patterns are excellent choices also in this case.
This article is part 3 of a series, further reading in parts 1 and 2:
Comparing light values – lumen, lux and candela?
What defines a good bike light pattern?