I bought a Lifan LF250-B and had a question why Lifan is using a non-standard 530 chain for the Custom 250?
None standard? 530 is the standard for many cruiser motorcycles, look at Harley-Davidson.
The only difference between a 520 or 530 is the width of the rollers, and of course weight, because of the extra material! Sprockets running with a 530 chain have more contact area, thus more load area, less sound, smoother, and usually last longer.