who knew a simple question could be such a topic of discussion.
i always thought K&N was synth material not cotton. they used to make some 'race' filters but they stopped doing that. i believe they made a green filter under a different name for a bit but that company died. the dry filters are good but they are a pain to clean. i always thought K&N worked on the oil that is applied to it, to make the dirt stick to an oily surface and then more dirt will stick to the oily dirt and so on.
i think when i got the K&N for my car, it said somewhere in the package to inspect and if it doesn't need cleaning just spray oil on it and put it back.

so i think ill pull the oem one out and take a look. i think for the money an aftermarket filter is the way to go.

too bad you guys can agree on a good brand, and that chart is for cars, half of those companies don't make bike parts. AC-Delco which is on top of the list, doesn't have a good selection for the CBR 600 Fx series.

 

Sorry I wasn't trying to hijack the thread, I'm just trying to give you the info so you can make an informed decision. I posted the link to illustrate k&n's lower filtration numbers vs. paper filters like baldwin, the no brand, and acdelco. I didn't say they made filters for the bike, the oem filter is paper and honda doesn't used crappy parts so I think you can trust it. Uni is included on the test, the amsoil filter tested was not the new nanofiber one so you can disregard that in terms of the filters you're looking at. The amsoil nanofiber filters are essentially paper w/ a kind of spider web nanofiber on top. It's a donaldson technology, but donaldson doesn't use it in traditional pleated filters like the amsoil design, they use it in their powercore filters which look like rolls of toilet paper. They also don't say it's cleanable like amsoil, those 2 things make me shy away from the amsoil. I am having trouble finding much on the S&S, probably not a good sign. BMC states their filters are 98.5% efficient vs. k&n's range of 96-99%.