CB650R Buzzing / Resonance Noise 5.5K to 6.5K RPM ('19 CB650R)

mcphatty · Oct 14, 2021

Have you checked the painted plastic shroud that goes around the ignition and onto the gas tank? I found that mine buzzed due to a misalignment of some of the velcro patches that hold it still. I still haven't gotten around to fixing it permanently, but I pushed a foam earplug into the gap to tighten things up and it addressed a significant amount of buzzing for me. Between that and a rubberband around the key, I've been able to eliminate most of the annoying buzzes on my bike.

Dankotaru · Oct 17, 2021

I had a buzzing that turned out to be the cable end piece for the clutch lever. I noticed that the noise disappeared whenever I had the clutch in. With the correct amount of lever free play there is no tension on the cable, and the cable end piece just vibrated inside the lever. I coated it in waterproof grease and the buzzing is gone.

Patent · Oct 19, 2021

mcphatty said:
Have you checked the painted plastic shroud that goes around the ignition and onto the gas tank?

This worked for me. My bike developed an annoying buzz and this thread led me to trying something with my keys. It wasn't my key but in doing so I discovered it was the plastic trim panel. I'm very happy it's fixed!

icemankent · Oct 28, 2021

UPDATE:
Oil change made things (seem) better, but the buzzing is not gone.
I will take a look at the plastic shroud next - mind you, I am also going to be putting my bike into storage imminently, as it is getting too cold out here lately to really enjoy any spirited riding. (i hate winter)

bishop · Oct 28, 2021

icemankent said:
UPDATE:
Oil change made things (seem) better, but the buzzing is not gone.
I will take a look at the plastic shroud next - mind you, I am also going to be putting my bike into storage imminently, as it is getting too cold out here lately to really enjoy any spirited riding. (i hate winter)

Check header bolts, horn mount.

icemankent · Dec 9, 2021

My bike is doing its winter sleep right now, but I did manage to get an audio clip of the sound.
Listen with headphones for the best effect.
EDIT: (listen to this on your smartphone). I just listened to the clip on my PC and could not easily hear the static/buzzing sound - using the pc speakers - Maybe my pc speakers are conditioning the sound somehow - filtering out the harsh frequencies.... When I browse to this site and play the clip on my phone - the sound in question comes through loud and clear --- exactly how it actually sounds when riding the bike.
The static buzzing sound happens at the higher rpm's.

xorbe · Dec 9, 2021

Yeah my new CBR650R rattles at specific rpms too, sounds like a plastic panel. Rattles are hard to find on motorcycles. Took me a while to find an rpm-specific rattle on my Speed Triple (clutch lever, and I don't see an obvious way to fix). I haven't poked at finding the source on the Honda yet.

icemankent · Dec 16, 2021

Yeah, the thing is, the sound is only present when actually (riding) the bike (i.e., it is in-gear).
Revving it up in neutral - even at the magic RPM range - will (not) produce the buzzing sound.
Therefore, it is more complex to troubleshoot.
There are some smart and resourceful people on this forum that may have better luck troubleshooting this once-and-for-all.

Atucker · Dec 16, 2021

icemankent said:
My bike is doing its winter sleep right now, but I did manage to get an audio clip of the sound.
Listen with headphones for the best effect.
EDIT: (listen to this on your smartphone). I just listened to the clip on my PC and could not easily hear the static/buzzing sound - using the pc speakers - Maybe my pc speakers are conditioning the sound somehow - filtering out the harsh frequencies.... When I browse to this site and play the clip on my phone - the sound in question comes through loud and clear --- exactly how it actually sounds when riding the bike.
The static buzzing sound happens at the higher rpm's.

That sounded exactly like my noise when the bike was new. It's been at least a 1000miles since mine has made that noise so I attributed it to something breaking in. No strange noise since, but I used to get it very often during a 2nd gear pull. Seemed like 2nd gear was the magic number for some odd reason.

xorbe · Dec 16, 2021

What about hums? My CBR seems to hum/resonate a sine wave type tone in 6th around 45 mph. Not a rattle, but "oooooooooo".

Atucker · Dec 16, 2021

xorbe said:
What about hums? My CBR seems to hum/resonate a sine wave type tone in 6th around 45 mph. Not a rattle, but "oooooooooo".

No idea. I've never been in that high of gear at that low of a speed. I tend to ride like its a rental. Every ride will see >10k rpm and I'm only going into 6th well after I've ran 3rd up to highway speeds. lol

JH09 · Dec 16, 2021

xorbe said:
What about hums? My CBR seems to hum/resonate a sine wave type tone in 6th around 45 mph. Not a rattle, but "oooooooooo".

JH09 · Dec 16, 2021

icemankent said:
Yeah, the thing is, the sound is only present when actually (riding) the bike (i.e., it is in-gear).
Revving it up in neutral - even at the magic RPM range - will (not) produce the buzzing sound.
Therefore, it is more complex to troubleshoot.
There are some smart and resourceful people on this forum that may have better luck troubleshooting this once-and-for-all.

where was the microphone when making that sound file? could it be the key or the key housing / shroud rattling around when under load?

volkein · Dec 17, 2021

JH09 said:
View attachment 11525

Mine was doing "WATATATA" in a tunnel this morning !

trippy · Dec 19, 2021

xorbe said:
What about hums? My CBR seems to hum/resonate a sine wave type tone in 6th around 45 mph. Not a rattle, but "oooooooooo".

The bike is saying "dooooooooooown shift" .

Motojack · Dec 19, 2021

xorbe said:
What about hums? My CBR seems to hum/resonate a sine wave type tone in 6th around 45 mph. Not a rattle, but "oooooooooo".

call the exorcist, you have a ghost in your crank case.

xorbe · Dec 20, 2021

In my defense I've had 8 bikes (yeah not that many), and none of them had a resonance hum like this, lol. It's really quite loud, it's weird. I'm not always on the gas ...

trippy · Dec 20, 2021

xorbe said:
In my defense I've had 8 bikes (yeah not that many), and none of them had a resonance hum like this, lol. It's really quite loud, it's weird. I'm not always on the gas ...

I don't think you need to defend anything. We were making fun of how you described it, not the actual vibration or riding style.

A better indication would be gear, rpm and exhaust. Some aftermarket mods (crash cages, racks) might also increase vibration.

My bike also has a "strange" vibration between 3200 and 3800 rpm. Stonger around 3400. It's something that neither the tunner or Honda mechanics could hear.

F6310JK · Dec 20, 2021

icemankent said:
My bike is doing its winter sleep right now, but I did manage to get an audio clip of the sound.
Listen with headphones for the best effect.
EDIT: (listen to this on your smartphone). I just listened to the clip on my PC and could not easily hear the static/buzzing sound - using the pc speakers - Maybe my pc speakers are conditioning the sound somehow - filtering out the harsh frequencies.... When I browse to this site and play the clip on my phone - the sound in question comes through loud and clear --- exactly how it actually sounds when riding the bike.
The static buzzing sound happens at the higher rpm's.

I just noticed this same sound on my 2021 CB when I was out on the weekend. It's just ticked over 4000km. The noise is most noticeable somewhere between 8-11k rpm.
I haven't tried any of these "fixes" yet, but found this post trying to find the answer.

icemankent · Mar 2, 2022

Good luck. Let us know.
There must be something, somewhere on this bike that is "loosening" over time - which is affecting a lot of us, eventually.
Short of disassembling the bike (fairings, etc) to get to the parts that cannot be easily reached, otherwise - I am at a loss as to where the vibrations are ocurring.
All I know is that it sure sounds like it is coming from the lower-front-right part of the bike.
Could be the headers, or anything else down there behind the fairings.
When spring finally arrives here, I am looking forward to an opportunity to investigate further.

...and as an answer to an earlier question - I recorded the audio on my smartphone - which was mounted in the center fork/hole.
(Quad Lock, with vibration dampener added). BTW, the vibration is (not) coming from that.