A strange howl

Before  I explain my problem I'll give you a brief rundown about the scoot. I bought it in September of last year and for numerous reasons I didn't get much riding in before the Canadian winter forced me to stop. I felt it was a bit 'wobbly' and didn't seem to go where I thought it should or wanted. I figured I would adapt soon enough. Over the winter I replaced all the fluids and replaced the belt. It only had 8,500 kms on it but I figured a new belt was prudent The other thing I did was replace the tyres which were the originals. I installed Michelin City Grip 2's. The scoot is now much nicer to ride and I've been able to get a bit of mileage on it this summer
On to my issue. I'm starting to hear a howl as I'm riding. It starts around 80 km/h and continues up past 100. The noise never changes and doesn't get louder as speed increases. I'm pretty certain it's coming from the front somewhere and last weekend I started taking more notice to see if I could figure it out Firstly,it is almost certainly coming from the front. I then realised the noise comes and goes pending the surface of the pavement. It also comes and goes if I gently sway off centre. This leads me to believe it's front wheel related. The bearings are fine and the tyre runs true with no vibration. It's a bit of a mystery and perhaps it was there last year and I just didn't notice due to me getting used to riding a different type of machine. It has a stock windshield, but I feel it's lower than that. More as if it's down by the floor boards.
On a final note I should say I'm hard of hearing and wear two hearing aids. I don't wear them while riding as they get uncomfortable and the noise gets pretty bad. This leads me to believe the noise is worse than I realise given I am capable of hearing it. BTW my partner says she can't hear it.
Sorry to ramble on a bit!! Anyone have any thoughts?

Charlie

Can’t say with certainty, but if you can hear it from the pavement, maybe it’s the tire or tires (a resonant hum). I recall certain brands of tires on other bikes, like the Honda ST1300 (from the forum) have resulted in a speed related hum. It’s not harmful of course, but to many they changed tires and the hum resolved. I’m not suggesting changing tires if they’re still in good condition, just something you may have to live with til the next tire change, assuming no mechanical issues otherwise.

Erdoc48 wrote:

Can’t say with certainty, but if you can hear it from the pavement, maybe it’s the tire or tires (a resonant hum). I recall certain brands of tires on other bikes, like the Honda ST1300 (from the forum) have resulted in a speed related hum. It’s not harmful of course, but to many they changed tires and the hum resolved. I’m not suggesting changing tires if they’re still in good condition, just something you may have to live with til the next tire change, assuming no mechanical issues otherwise.

The tyres are new and maybe a trait of the City Grip 2's It's installed in the correct rotation and the pressure is as per the manual.

Sounds to me like a Tupperware howl.
You only notice it on a Swing at higher speeds
Have you tried temporarily blocking the top front air vent, then try to two bottom ones, then all of them.
If it was a bearing issue, the pitch would vary depending on speed
Hope this helps.
Be safe, be seen!

Ooh, just thought, the front fender has a steel, arched brace under the plastic (part no. 2)
it's glued to the fender with sticky foam. That makes a constant noise at higher speeds when the glue fails.
A good adhesive sealant will cure that, remove fender and bracket and glue back together, then re-assemble.

I'm thinking it must be body work as it never varies in pitch as you would expect of a bearing or tyre. I'll do a bit more investigation with the vents. The front mudguard was removed over the winter when I installed the Hyper Pro springs. Worth a look. Cheers

welshman in canada wrote:

Erdoc48 wrote:

Can’t say with certainty, but if you can hear it from the pavement, maybe it’s the tire or tires (a resonant hum). I recall certain brands of tires on other bikes, like the Honda ST1300 (from the forum) have resulted in a speed related hum. It’s not harmful of course, but to many they changed tires and the hum resolved. I’m not suggesting changing tires if they’re still in good condition, just something you may have to live with til the next tire change, assuming no mechanical issues otherwise.

The tyres are new and maybe a trait of the City Grip 2's  It's installed in the correct rotation and the pressure is as per the manual.

I also had this "problem" on my SW, but the "howl" came from the rear where a Michelin City Grip was running. I never cared much and it was the same, as it only happened when it turned straight, disappearing, at the slightest inclination, to the right or left. I changed the tyre to a Bridgestone Hoop, just like at the front and that "howl" just disappeared. It may be a characteristic of these tires...

I know you said you usually don't wear your hearing aid on the bike, but if you do is the noise still there and the same? I'm asking this because hearing loss often affects only certain frequencies more than others.
The fact you says the howl comes and goes with different road surfaces makes me think it's just a characteristic of the tyre - although I would be keeping an eye on the wheel bearings in case one of them is getting on the way out.

I also occasional hear a howl on my front tire, usually at higher speeds, when I tilted scooter, change directions suddenly (evasive maneuvers ) or on sustained/fast leaning turns I checked the normal stuff (installation/bearings/pressure), nothing. Increasing air pressure to 30-32 psi helped some, I also believed it was the cheaper Shinko tires, maybe related to thread design, but the City Grips are completely different, so

I went for a ride a day or so ago and the 'howl' had gone. It was a good 15 degrees c cooler than previous rides so i guess the issue is temperature related so it's more than likely the front tyre. I can live with that

I also have city grip 2s front and back.
Yes they do produce a hum on pavement and louder in some types of pavement. The hum is more noticeable in the front as the sound travels up through the vents and fairing.
Mine is an 05 S. W. 600 with 30.000 miles on it.
I have 3000 miles on the city grips and they are wearing fine, still look like new ,good traction ,excellent in heavy rain downpours.
Prior to these tires i had diablos on it,
I like the city grips.
I run 30lbs front and 36 rear .