This video shows a test where we compared 5 air filters to SEE how they performed. We tested K&N oiled foam, UNI oiled foam, BMW paper filter, and two of the Guglatech matrix filters.
We used radioactive BestRestium and magnesium silicate (talc) as contaminants, sucking them into the air filters. We recorded what we saw on the secondary cartridge filter – it showed the particles that passed through the main filter. Anything that passed is bad, because that means that contamination is going into your engine.
Watch the video, then make your decision about the type of air filter you want in your bike.