So I’ve got a bit of a rattle going on on/in my Nightster and I can’t figure out what it is. I think it’s done it since I’ve owned it but once I got my new chain and sprockets fitted I swear it’s way more noticeable. I thought it would have had to have been the kickstand but I’ve zipped tied it to the frame and also tried flicking it down with my boot while travelling along trying to replicate the sound and just cannot get it. The odd thing is it’s only really while the throttle is open and it only occurs when you’re hitting bumps in the road, on a nice smooth bit of black top it won’t do it whatsoever, no matter the RPM’s or gear but hit the right kind of bump in the road and it’ll rattle, sounds like a bit of tin touching the frame but I’ve gone over it time and time again and can’t find shit. I have heard it only for a split second when hitting bumps with the throttle shut but it almost never does it unless it’s open, regardless of the degree to which it’s open. 

I’ve tightened my primary chain, it was a bit loose and I topped the transmission fluid up but it’s still just a touch under where it should be (waiting for the fluid to come in the post, local dealer is shut for the holidays for another week) but it’s still covering the chain. I’ve checked any suspect bolts and have found nothing. 

It runs and rides like hell, it’s super reliable and since I’ve had all the tuning done it’s riding brilliantly but this rattle is driving me up the fucking wall. If anyone has any ideas it’d be much appreciated! Can’t find shit on google. 

And it’s definitely not pinging, been through that shit already! 

Cheers ladies and gents! 

Is it a rattle or a thud/thump?

- check rear swingarm bushes and bolts as they wear

- steering head bearings can knock when worn (or even a loose steering bolt)

- Check the front fork oil levels and in fact just replace it anyway - low oil can cause noises there.

check your side stand, spring and bracket

may be that simple

Looking at doing a transmission service possibly this weekend, would it be worth getting a gasket kit and taking the primary cover off while it’s drained and having a sniff around or generally is the chain the only thing that could be making the noise? The clutch was also brand new less than 6000 kms ago so I’m highly doubtful that could be the issue. It’s got me buggered this one does.