Time to replace the rear brake pads?

[luvmyguys]

Amen. Wipe the rims down with rubbing alcohol and see if that helps.

That's exactly what I did last night. Didn't help.

ETA: I'll try lightly sanding the pads.

[Hi Ho Silver]

If the brakes didn't squeal before cleaning the bike, then the squeal is the result of stick-slip behavior - the pad is sticking to the rim too well. I experience this on my bikes after I give the rims and pads a good cleaning with soap or degreaser. The easiest cure I found was to dab some talcum powder on the rims' braking surface, activate the brakes a couple times, then thoroughly wipe the powder off the rims and the pads with a dry cloth. Be forewarned, the first few times you brake after this, you might not get your usual full braking power.