Today i noticed a squeaking sound from the rear. With the engine off if i push it is when it's easiest to hear, and what it sounds like is rubber squeaking. Like if you are in one of those underground garages or some such surface thats real slick and you hear the tire squeaking against the glossy pavement. It's random as i move it, not totally constant. i looked at the belt front to rear (removed cover) and the tire to see if either was rubbing on something. any ideas?
Any chance that the wheel is bent? A weak section of the sidewall of the tire flexing a bit more than the rest of the sidewall? Easy test is to set the bike upright on a jack, place a 4x4 with tire chalk strapped to it on a stool so that you can put just the tip against the sidewall on both sides and dead center of the tire (three tests or three chalks one test) rotate the wheel slowly just once, but break it up in 90 degree sections (a quarter of a turn at a time and re-adjust the chalk if needed). Deviations in the chalk patterns will tell you if and where there a problems.
Fast and nasty but definately more dangerous. With the rear wheel suspended, the engine running and bike idling in first gear, take a long shank screw driver (at least 12 inches) business end in your gloved hand, gently lay the handle on the moving tire with very light tension. Slowly bring the handle across the tread. You will feel the deviations if they are there. A long 3/8 drive extention will work just don't let the end touch the tire use the round part of the shaft.
The tire should be suspended off of the ground for a minimum of 2 hours, over night is best, this lets the flat spots from ground contact when parked even out. They won't affect your tests this way.
In case your wondering, these are shade tree mechanic tests to determine if a wheel is bent or a tire is out of round or has a bubble between the tread and the belts or the bead rolled on the rim. We did these before looking at the more expensive possibilities.
Of course you can always take the wheel into a shop that can spin balance the wheel. But where's the fun in that?