CB650R Unknown gear/chain/engine noise, need help diagnosing

[Brammers]

^ this

 

[HornetRocket92]

Hello!

Recently I've noticed a noise that seems to be emanating from the front sprocket area of my bike, and I cannot for the life of me find out what's causing it- to the point that I'm wondering if it's always been there and I'm only just now noticing it.

The sound seems to be related to engine load, and is most noticeable when accelerating in too high of a gear. It seems that the noise is not coming from the exhaust, since pulling my legs away from the body of the bike makes it more audible, leading me to think it's engine/transmission related. There's about 5000 miles on the bike.

Audio only - I had the phone in my pocket while riding around.


Mystery noise is most noticeable in the video at 23 seconds, but can also be heard at 11 seconds and 16 seconds. The specific noise I'm referring to is the high-pitched buzz/whine that seems to be secondary to the exhaust note.

I checked my chain for slack and wear, and did not see anything beyond what seemed normal. Slack position is well within the green marks, and nowhere close to the red. To test a theory, I tightened the chain and went for a short ride and also loosened the chain before a short ride. Either situation did not have any impact whatsoever on the noise. I opened up the cover for the front sprocket to inspect for debris and aside from a little bit of slung chain oil buildup, everything was normal. I did clean out the excess lube while I had things apart, but that that did not seem to affect the noise either. Additionally, I bought a chain alignment tool to check alignment, and the chain was aligned properly.

At this point, I'm out of ideas (well, mainly the tools to inspect things further) as to what it could be. Am I hearing something (my wife says I never hear anything, but that's unrelated) that could be an issue or am I just noticing a totally normal noise?

I doesnt let me to see the video it says i have to get permission from the uploader of it