The impossible tech question...

[Smokescreen]

Just as and aside, my06 S2R 1000 was making some tapping noises and otherwise acting up and I failed to take note when I changed the belts that one was a bit worn on its smooth side.  The new belt was eaten through about 60% before I realized that one of the idlers was frozen and eating the belt, and I'd gone one tooth off to boot.  Now that these issues are fixed the bike runs well, but unlike MonsterGrrl's M900 (the other bike I've spent a lot of time on and under) the S2R has a sound similar to supercharger whine and it's more evident under engine braking (probably because the exhaust is a little quieter).  I attribute this to the tighter belt tension numbers on the DS motor.  However, this doesn't mean I intend to run at lower tension numbers as the service manual for the DS makes note of much tighter belt tension.  It's the way it's supposed to be, right down the the pricier belts with no aftermarket manufacturer. 

I will point out however that the bearings on the belt tensioner were toast before 12 thousand miles.  I only make this note as a reminder that they should be checked with some regularity.  If I'd blown a belt, I'd likely have blown the motor.  The easiest way to tell that a tensioner bearing has failed is wear on the backside of the belt. 

Also, the belt tensioner bearings can be purchased but the tensioner unit (in case like me, your bearings have welded themselves on) has been superceded by a tensioner with integrated bearing.  Probably it's better just to purchase this. ($75) You will note the the integrated bearing is a smaller diameter than the older slip on bearings.  I don't know why this is, but it is ok nonetheless.

Hope this is a little help.