2012 S40 with 6,000 miles. On a four bike family ride yesterday, with me in the #1 or #2 position and my son always #4, he kept hearing a squeak coming from my bike. First he thought is was me beeping my horn then later, he seemed to think it was when I would hit a bump- maybe bottoming out. I wear a hearing aide, but when I ride I wear one ear plug instead, so I didn't really hear it.
So- today I took the bike thru its paces without an earplug, but no hearing aide either. What his was hearing is a squeaking that I've heard since I got the bike new, but I guess I've just gotten used to and tune it out.  

It sounds like "nyeeek" and is present when I release the clutch going up or down thru each gear. It is  slightly sustained "nyeeeee" after releasing the clutch on the downshifts. I've just thought it was intrinsic to this bike and have never owned another to compare.

Comments?

"We are the Nights that say Neeee!"

Do you get any squeeking if you bounce up and down on the seat?

Do you get the noise if you pull the clutch in and out when the engine is turned off, or if the engine is running and the transmission is in neutral?

Ok- to answer some of your responses.

1. No factory warranty left.
2. No squeaking went bouncing up and down on seat.
3. No noise with engine off and pulling on clutch lever.
4. No noise running and in neutral.
5. No speedometer, headlight or covers loose/rattling.

So- I'll find the belt alignment info on the forum and do that check next ( after I finish my new motorcycle jack adaptor plate project) and report back. Thanks everyone.

Prove it's the belt before you put time into it.  You can rub wax or soap on the edges,
If that stops or changes it,you might be onto something.might wanna get some on the teeth,too.
The front pulley can get a little loose and make noise,but I don't remember anyone who has ever reported a "nyeek" sound,but the cost and pain that problem causes would have me checking it out if I couldn't find what is doing it right away.

OK- I just checked the belt. At the point I started rotating the tire, the belt was in the center of the rear pulley for about half a rotation. Then It drifted to the left just enough to be touching the left shoulder of the pulley for about a quarter of a turn then to the right until it touched that shoulder. That doesn't seem like much movement. Is that worth trying to correct?
Also I found that I can hear the squeak when I rotate/back-off on the throttle quickly without squeezing the clutch in all gears.                                                                                                                  

And,before you go spend time on it,you can Prove it Is the belt in a matter of minutes. Or,you can go spend time fighting the belt and hope that is the problem. I'm betting it is the problem,but before I knew,I would not want to get involved in it. Just wax it and see if that kills or changes the noise.
How much time have you spent trying to figure it out since I told you the quick,easy way to prove to yourself it is the belt? More than it would have taken to wax it and know for a fact,I guarantee you.

Really,Dave? Why not Start with proving that the belt Is the source? I bet it is,but until he KNOWS he can't be sure what he is fighting.
Once he can definitively say that the noise is from the belt,then it's time to start looking at why the belt is making noise. Until I hear that the belt has been waxed,you guys can keep solving the problems that are not even isolated yet.

I had this thing happen when my belt was a tad too loose. It wandered all over, and made noises both on downshift and engine braking..a loud "whee". Could be it just needs tightening up a wee bit.