Some of y'all might find this of interest-K&N vs standard paper filters

you seem to be under the impression any of us can afford a K&N


it's strictly air filters off eBay made from finest Chinesium, or an oily kitchen sponge!

Stick with the chinesium filters or washing up sponges, they're probably better all round than K&Ns.

Did you read the test?
Doesn't make me want to go for K&N really.

For a realistic but possibly cheaper air filter than the cheapest bike one, you could try this route if you can be bothered:
https://www.tdm-yamaha.heliohost.org/?page=FL9

I've bought a used TDM9 and was pleased to find a previous owner had installed a K&N, until I saw the test showing how much crap they let through compared to paper filters- not sure the possible minute hp gain is really worth it.
Wemoto stock a cheaper copy of a K&N it seems, like £60 cheaper!

There's a youtube vid somewhere of a guy comparing car filter types. He has a sealed perspex booth with a central partion where the air filter is mounted.

On one side of the partition is a thing that makes dust particles in various sizes and on the other is a a fan and a particle measurer/counter.

The difference between paper, high density foam, low density foam, a K&N and K&N knockoff cone filter was pretty amazing. The K&N and K&N knockoff were the worst of all, the knockoff being only a fraction shittier than the k&n.

Though when it comes to how important that is there's gonna be a hell of a difference between someone riding about in damp old England so someone offroading in a dustbowl every weekend.

The K&N on my VFR has more than paid for itself. There's generally very little shite in it anyway when I clean it out. I doubt this is because it's letting the shite through, more because it doesn't suck in much shite in the first place. By the time the air has got past the fairing, under the tank then done two 90 degree bends, any crap will have been left behind anyway. The filter is really just applying preload to the CV vacuum so the slides open properly and maybe forcing better laminar flow.

I switched to pipercross foam sock type filters a while back and I prefer em over k+n on account of them handling wet weather a bit better.

Not much of a problem to you airbox types but for us idiots putting the wrong engine in things with no space or motivation to create an airbox it does help.