2009 K1300GT hum at about 110kph to 120kph

[Jimb442]

I am getting a hum at about 110 to 115+ kph and it's significant.

Details:
Sounds like it's from the front but can't be 100% sure. Hum only occurs when bike is riding straight up. Any lean at all and the hum is all but gone.
Front tire brand new today as I thought it must be the tire because the bearings were done last summer. Rear tire new last summer and lots of tread left.

thoughts?

Feel free to email me at Jimc40@yahoo.com

thanks.

[dirtrider]

18 minutes ago, Jimb442 said:

I am getting a hum at about 110 to 115+ kph and it's significant.

Details:
Sounds like it's from the front but can't be 100% sure. Hum only occurs when bike is riding straight up. Any lean at all and the hum is all but gone.
Front tire brand new today as I thought it must be the tire because the bearings were done last summer. Rear tire new last summer and lots of tread left.

thoughts?

Feel free to email me at Jimc40@yahoo.com

thanks.

Afternoon  Jimb442

 

That usually sounds like tire issue but a lean to diminish  can also be indicating an air flow problem. Can you you get it at a lower speed  if you ride into a strong wind? Or does a side wind change it?

[Jimb442]

thanks for the response.  As I mentioned front tire is brand new and rear new last summer with plenty of tread left.  a decent side wind of course will make you lean so though the hum will go away it's tougher to notice because of wind noise but yes even a relatively small lean and the hum practically disappears.  Just weaving back and forth in my own lane is enough to make the hum come in and out as the bike goes from lean to straight to lean.  Hum does not happen at anything under about 105 to 110kph.  Not sure what you mean by air flow problem?

[wbw6cos]

What brand of tire is the front?

[Jimb442]

It was a Michelin Road 4 (GT I think) with quite of bit of tread left and now a Michelin Road 5 Gt.  Same hum with either.

[wbw6cos]

I did not want to interfere with dirtrider's posting as I was curious about the tire brand.  I have read about Michelin tires being noisy and I am not saying that is the root cause of your issue, but I have the Road 5 GT tires on my RT and do notice noise (hum?) coming from the tires.  I cannot say for certain if the noise disappears in a lean, but I will have to listen for it now.    I do not think the tires made that nosie when it had Metzelers on it previously, but......

[dirtrider]

1 hour ago, Jimb442 said:

thanks for the response.  As I mentioned front tire is brand new and rear new last summer with plenty of tread left.  a decent side wind of course will make you lean so though the hum will go away it's tougher to notice because of wind noise but yes even a relatively small lean and the hum practically disappears.  Just weaving back and forth in my own lane is enough to make the hum come in and out as the bike goes from lean to straight to lean.  Hum does not happen at anything under about 105 to 110kph.  Not sure what you mean by air flow problem?

Evening  Jimb442

 

That does sound more like tire noise, probably rear as a new front didn't change it.

 

Try letting a little air out of your rear tire as a test to see if that changes the noise (if the noise changes with an air pressure change that pretty well points to a tire)  

[Jimb442]

Thanks wbw6cos.  I will try the air pressure Dirtrider.