Bike light FAQ
Question: What does “German approval mark” mean?
Answer: Lights on vehicles such as cars or bicycles are subject to statutory requirements. In Germany, the StVZO (German road traffic licensing regulations) regulates the “technical lighting setup on bicycles”. Here, it is specified which requirements a front or tail light must satisfy. Whether a manufacturer meets these specifications is reviewed by the Federal motor transport authority. If a bike light complies with the requirements, this model is given a “K-number” or approval mark. This approval mark confirms that the lighting complies with StVZO.
Question: Am I allowed to use lights on my bike that do not have any approval marks?
Answer: If I am moving in road traffic, I must ensure that my lighting is StVZO-compliant. The rules in the German road traffic regulations ensure that all road users are protected. Non-StVZO-compliant lighting may dazzle other road users and thereby pose a risk. The only exception here are personal safety lights that are worn on the body or clothing and serve as additional lighting.
Question: What is lux?
Answer: The lux unit of measurement measures the illuminance on a surface and is comprised of the luminous flux (lumens) and a unit area. The illuminance of 10 lux corresponds to 10 lumen per square meter. With bike lights, the lux number is measure only from the center of the light beam.
Question: What does lumen mean?
Answer: The lumen unit of measurement indicates the strength of luminous flux and measures the luminous intensity projected in a given solid angle from a light source. Thus, lumens say something about the radiation power of a light source.