HilltopMark
Registered user
While there's no doubt that changing your filter to an aftermarket one can increase airflow, do these free flow filters clean the air as well as an OE filter? Based on the rather cynical idea that there's no such thing as a free lunch I would say 'no', and that if an aftermarket design cleaned the air as well but flowed it better than the paper filters that all OEs currently use then filters of said design would be standard fit on all bikes in the blink of an eye. Anyway, someone has actually been to the trouble of testing some of these filters. Good for them (and us):
https://www.bobistheoilguy.com/airfilter/airtest1.htm
https://www.bobistheoilguy.com/airfilter/airtest1.htm