What could cause a Hum on the freeway?

[syphon]

My bike has a distinct "hum" to it when I'm at speed (like on the freeway). It's loud enough to be heard over the wind... which is something even my exhaust can't do! (just poking a little fun at my really quiet bike).

My chain is tightened and lubed correctly, I don't see any immediate problems with either of the wheels or tires. Is there something common that causes a hum at high speeds? It almost sounds like a worn wheel bearing or something, but I don't know if that's it, since my bike is an '02 and the bearings shouldnt wear out that soon.

I'm really cautious about any noises I hear on the freeway... as a mechanical failure on a bike can be much more disastrous compared to one on my car!

Any help is appreciated.

[jordanearl]

could it be the tires, never noticed a real loud hum, but can definetly hear them a bit, im my truck(F-150) i can definetly hear the tires hum down the highway

[l3uddha]

could be the faring vibrating when you get up to highway speeds... mine does that

[syphon]

It's an '02, so no Fairings

The ride home today had a pretty noticable hum. Even at slower speeds.... I can almost feel a little vibration along with it.

Everything seems to be ok... the only odd thing I noticed is that the front brake caliper felt a little loose. Is it supposed to be like that? It was held on there ok, but I could wiggle it around a little (the rotor and wheel are nice and tight though).

[MarkusN]

You are not talking about the 5000 RPM tank resonance, are you? (Don't know if the post 2000 Models have it, though, since the design of the tank has changed.)

[syphon]

No, although I get that too. I was going to make a thread... "why does my bike rattle at mid-range RPMs?" Can you tell me more about this issue with the tanks?

[MarkusN]

It's not really an issue. Just a harmonic resonance of the tank with engine vibrations at certain RPMs. Think of it as one of the GS's quirks, like valves ticking.

Most mechanic systems have resonances in one part of their RPM range or another. Some are harmless, like this tank rattling. Others are downright catastrophic, like a tank slapper.

If the tank rattles loudly something may be wrong with its rubber supports. That should be dealt with, as it causes wear.


On the hum: The front brake rotor hums. I especially notice that with sintered pads with the brakes just barely engaging. Maybe your pads are dragging?

[Wrecent_Wryder]

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[Wrecent_Wryder]

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[LPC2104]

I've noticed that my bike has a little hum or vibration when I'm low on gas. 

[jdanna]

SO THATS WHAT THAT NOISE IS!

I figured it was hitting some part's resonance freq around 5k-6k, so i didnt worry about the noise.
But I always kinda wondered what it was

[RVertigo]

The ride home today had a pretty noticable hum. Even at slower speeds.... I can almost feel a little vibration along with it.

  Yeah...  Something is wrong...  It's a NEW thing right?  Not just the 5k buzz, not an empty fuel tank vibing more than usual... 

Does the hum change pitch with speed?  Get louder with speed?

Your chain isn't TOO tight, is it?

Could be bearings or something with the brakes...  You might bite the bullet and take it to a shop...     Better to be poor and alive...

Damn...  I was gonna see if you wanted to ride this weekend...