Air Filter On A 900

I've had K&N filters on bikes in the past (wouldn't use one again though) and it made no difference I could tell to noise levels so I doubt it will affect the 900 twin unless you're modifying the airbox which can increase induction roar. I don't think a filter on it's own would make any difference to performance without other mods such as exhaust, fuel maps, cams etc. I also like the look and sound of the standard exhaust, similarly on the 1200 but then I'm not a fan of excessively loud exhausts while riding.
I got stuck in traffic one day last week, sat behind an old Harley of some description with very little silencing and the rider insisted on continually blipping the throttle. I could have got off and punched the annoying fecker. What a tw*t!

 

I have used K & N air filters on a number of bikes I have owned over the years. I have never noticed any increase in noise or performance. The advantage, as far as I am concerned is the fact that they are serviceable and do not have to be replaced as is the case with a paper filter.

 

Any after market (louder) exhaust makes me feel like that. There’s a group of us go touring at least once every year and we do not let anyone with after market exhausts or small number plates join us. We do not want or need any attention drawing to us. We also don’t want to annoy other people.